Methods and apparatus for enabling proximity services in mobile networks

ABSTRACT

Apparatus, system or method to improve communications in a wireless communication network. Steps may include sending specific information to user equipment or adjacent base stations so that the user equipment and adjacent base stations can determine interference levels in sidelink communications. The apparatus may include a location-estimation component interconnected with a self-tracking component and a signal-detection component. The apparatus may include a proximity system implemented using instructions stored in a non-transitory computer readable medium and the proximity system may be usable to locate one or more target transmitters. In some embodiments, the system may include other modules such as a localization module; a proximity-description module; and a proximity-display module. The proximity system may also include a proximity advertisement module, which includes an access management component; an ownership management component; and a content management component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. patent applicationSer. No. 15/112,173, filed 16 Jul. 2016; application Ser. No. 15/112,173was a continuation of, and a national stage entry of, PCT/US2015/058819filed 3 Nov. 2015 with article 19 amendments filed Mar. 14, 2016;PCT/US2015/058819 claimed the priority benefit of U.S. ProvisionalApplication No. 62/085,327, filed 27 Nov. 2014, and U.S. ProvisionalApplication No. 62/235,697, filed 1 Oct. 2015; the entire contents ofall of these applications are hereby incorporated herein by reference.

TECHNICAL FIELD

In the field of wireless communication systems, methods and devices aredisclosed that enable individual mobile devices to determine if a deviceto device link within a cell may be created and how these devices shouldcommunicate.

BACKGROUND

This Background section of this specification is intended to provide abackground or context to the invention that is recited in the claims.The description herein may include concepts that could be pursued, butare not necessarily ones that have been previously conceived or pursued,and thus should not be considered prior art unless it is expressly sostated.

The following abbreviations that may be found in the specificationand/or the drawing figures are defined as follows:

-   3GPP: third generation partnership project;-   ACK/NACK: acknowledgement/negative acknowledgements;-   AP: access point;-   API: application programming interfaces;-   ACCS: autonomous component carrier selection;-   BAC: blind admission control;-   CDF: cumulative distribution function;-   CUE: cellular user equipment;-   CQI: channel quality indicator;-   CRC: cyclic redundancy check;-   CSI: channel state information;-   DAC: distributed admission control;-   D2D: device to device;-   D2DBSIE: device to base stations information element;-   D2DIE: device to device information element;-   D2DIE2: device to device information element 2;-   dB: decibels;-   dBm: decibel-milliwatts;-   eNB or eNodeB: E-UTRAN Node B (evolved Node B/base station); used    interchangeably with “access point”;-   EPC: enhanced power control;-   E-UTRAN: evolved UTRAN (LTE);-   FDM: frequency division multiplexing;-   HII: high interference indication;-   IP: Internet Protocol;-   LTE: long term evolution;-   LTE-A: LTE advanced;-   MAC: media access control;-   M2M: machine-to-machine;-   OAC: optimal admission control;-   OLPC: open loop power control;-   P_(D): power control function;-   PDCCH: physical downlink control channel;-   PHY: physical layer;-   PMI: pre-coding matrix index;-   PRB: physical resource block;-   ProSe: proximity-based services;-   PSCCH: physical sidelink control channel;-   PSSCH: physical sidelink shared channel;-   PSD: power spectral density (dBm/Hz);-   RSRP: reference signal receive power;-   RE: resource elements;-   RI: rank indicator;-   RS: reference signals;-   SCI: sidelink control information;-   SINR: signal to interference plus noise ratio;-   TPC: transmit power control;-   UE: user equipment, where UEs is the plural;-   UL: uplink (UE to eNB);-   UPP: universal plug and play;-   UTRAN: universal terrestrial radio access network; and-   WLAN: wireless local area network.

The following definitions of terms used herein are applicable:

-   3GPP: The 3rd Generation Partnership Project provides specifications    that define 3GPP technologies;-   “access point”: In cellular networks like LTE-A, it is a conceptual    point within the radio access network performing radio transmission    and reception: An access point is associated with one specific cell,    i.e. there exists one access point for each cell. It is an end point    of a radio link. In other wireless systems like Wi-Fi, it is a    device that allows wireless devices to connect to a wired network    using Wi-Fi, or related standards; “Access point” in this    application refers to a conceptual point within the radio access    network, unless otherwise specified;-   “base station” or “eNodeB” or “eNB”: A base station is a network    element in radio access network responsible for radio transmission    and reception in one or more cells to or from the user equipment.    Each eNodeB has a baseband processing unit. Each baseband processing    unit is connectable to multiple radio units (either remote radio    heads or radio cards), which enable transmit and receive functions    involving radio frequency signals. Thus, each radio unit is    connected to one or more antennas serving a particular direction,    and thus forming a sector or a cell (in the logical naming sense),    as shown in FIG. 2B;-   “cell”: A radio network area that can be uniquely identified by a    mobile terminal from a (cell) identification that is broadcasted    over a geographical area from one access point.-   “D2DBSIE”: parameters or signalings that carry stastical information    of the tolerable performance loss of the primary UEs such as for    example, the total amount of interference from the device to device    links that is tolerable by the user equipment in an uplink;    propagation constants related to a channel model; coverage area for    device to device links; and an average sum of channel gain of    existing device to device links to the base stations.-   “D2DIE”: parameters or signalings that carry statistical information    of existing active device to device links, such as for example,    density or number of active device to device links; propagation    constants related to a channel model; and a coverage area for device    to device links.-   “D2DIE2”: parameters or signalings sent between adjacent access    points or base stations and may include the density or the number of    active device to device links in the serving area of the base    station and may include a high interference indicator for sidelink    communications in the wireless communications network;-   “D2DIE3”: parameters or signalings sent from one user equipment of a    device to device pair to adjacent base stations to indicate that in    the near future, potential transmission between the sidelink (device    to device) communications will be scheduled in certain parts of the    radio resources, These include bandwidth, frequency division    multiplexing (FDM) symbols, or resource blocks, by the device to    device pair.-   “user equipment” or “UE,” or “mobile terminal” or “terminal” is a    device that allows a person to access to network services. The    interface between the UE and the network is the radio interface;-   “PSCCH”: Physical Sidelink Control Channel, a transmission resource    pool and physical channel defined in a sidelink carrying the control    information. A physical channel is defined by code, frequency,    relative phase (I/Q), or time-slot, and so on; and-   “PSSCH”: Physical Sidelink Shared Channel, a transmission resource    pool and physical channel defined for a sidelink carrying data.

More and more devices are becoming connected. Market research by otherssuggests that in 2020 the total number of connected devices will growfrom 9 billion today to 24 billion, with half incorporating mobiletechnologies. These connected devices can be devices such as smartmeters, but increasingly all kinds of consumer electronic devices (e.g.photo cameras, navigation devices, e-books, hi-fi equipment, andtelevisions) are connected. Many of these connections are among devicesin close proximity and there is evolving demand for enabling proximityservices from different perspectives. This is described in CISCO, “CiscoVisual Networking Index: Global Mobile Data Traffic Forecast Update,”2014. For example social apps, hyper-local marketing and classifieds maybe based on proximity.

Proximity will also be a new vector for mobile advertising and therewill be growing need to enable new types of advertising for proximityservices. For example a customer in a mall will prefer to receiveinformation or ads related to the shops inside this mall, rather thanthose worldwide.

Many consumer electronic devices will need to communicate with otherconsumer electronic devices in their neighborhood. For example a photocamera can communicate with a printer, or a media server can communicatewith hi-fi equipment.

Providing proximity-based services enables consumers to interact withtheir proximate environment in a spontaneous and direct way using theirsmartphone, and thus bring about a huge array of benefits for theconsumer, for enterprises and in turn, for the operator.

As a value-added-service, proximity-based services offer the potentialfor huge gains for operators, including additional revenue gained fromthe consumers from access to services, from new marketing tools forenterprise customers, and from opportunities for revenue sharing withthird-party's via developer Application Programming Interfaces (APIs).

A major economic opportunity of proximity-based services is for mobileoperators to hold the rights to the spectrum that enables thisfunctionality. The party holding the rights to the spectrum could act asa gatekeeper, controlling access to the services.

The start-of-the-art research and inventions related to proximity-basedservices and technologies may be summarized by a discussion of the 3rdGeneration Partnership Project (3GPP). The 3rd Generation PartnershipProject unites multiple telecommunications standard developmentorganizations and provides the means to define systems for cellulartelecommunications and network technologies.

IEEE 802.11 is a set of media access control (MAC) and physical layer(PHY) specifications for implementing wireless local area network (WLAN)computer communication in the 2.4, 3.6, 5, and 60 GHz frequency bands.The IEEE802.11 is hereby incorporated by reference herein. The IEEE802.11 specifications are created and maintained by the IEEE LAN/MANStandards Committee (IEEE 802). In IEEE 802.11, the primary UEs are thedevices that communicate directly to the access point while the deviceto device pair could be two devices that communicate directly to eachother. Within 3GPP, Proximity-Based Services (PBS) provide discovery ofdevices and communications between devices in proximity. Thus,Proximity-Based Services support communication between devices that arephysically located close to each other.

Device-to-device (D2D) communications is enabled by cellular networks,e.g. 3GPP infrastructure that provides a generic communicationcapability that can generate a new revenue source for mobile networkoperators. As proximity based applications are growing fast, the demandof Device to Device communications will increase dramatically.Developing scalable Device to Device communications for systems like3GPP is of paramount importance.

The main idea of Device to Device communications is to enable twodevices in proximity to communicate directly with each other,re-utilizing the resources of primary cellular networks or using a setof orthogonal resources. Its impact on the performance of existingcellular UEs should be minimal. For example in Long Term Evolution-A,device to device links may share the uplink resources of the cellularnetwork or use orthogonal resources.

When downlink resources are reused, device to device links may causestrong interference towards existing cellular user equipment, whereas inthe case of sharing uplink resources, the interference caused by deviceto device links will affect only the base stations, where the impact hasbeen determined to be less harmful.

As more device to device pairs exist in the network, the interferencelevels may increase to a point where the performance of both cellularand Device to Device networks could be seriously degraded. Thus, one ofthe main limitations on the scalability of Device to Devicecommunications is interference control. To solve this potential problem,a careful interference coordination and power control technique is usedto have scalable Device to Device communications to assure quality ofservice to both Device to Device UEs and existing cellular UEs.

When device to device links are added to the system, two main levels ofinterferences are generated: 1) A first level of interference caused bythe cellular network, namely from existing cellular user equipmenttowards other base stations (inter-cell interference) and from CellularUser Equipment towards device to device links; and, 2) a second level ofinterference caused by Device to Device network, namely from device todevice links towards the base stations and from device to device linkstowards other device to device links.

The first level of interference includes inter-cell interference. In theuplink of the last generation cellular networks the resources withineach cell are allocated orthogonally resulting in zero intra-cellinterference. However, the resources are shared by several cells causinginter-cell interference between the Cellular User Equipment and basestations of different cells. This problem is well known and there hasbeen important research done in the last years.

There are numerous studies and proposals that form the background ofaddressing cellular interference. One proposal includes an adaptive softfrequency reuse scheme that decreases inter-cell interference improvingthe average throughput per UE. Another recommends an interference awarejoint scheduling scheme based on proportional fairness. Others havestudied the problem of resource allocation considering the impact ofinter-cell interference while maintaining a frequency reuse of one.Studies have been published on the evaluation of the Long Term EvolutionOpen Loop Fractional Power Control and the closed loop power controlconsidering the impact of inter-cell interference while giving aninsight to the proper configuration of the design parameters.

For example, in the conventional power control for sidelinkcommunications, the transmission power control formula for PSSCH orPSCCH is

$P_{D\; 2\; D} = {\min\begin{Bmatrix}P_{{CMAX},c} \\{{10\;{\log_{10}\left( M_{D\; 2D} \right)}} + P_{O\;\_\; D\; 2D} + {\alpha_{D\; 2D} \cdot {PL}}}\end{Bmatrix}_{dBm}}$

where P_(CMAX,c) denotes the maximum UE output power on cell c andM_(D2D) denotes the D2D transmission bandwidth in number of PRBs for thecorresponding channel, e.g. PSSCH or PSCCH. P_(O) _(_) ^(D2D) andα_(D2D) are the two power control parameters (1215) that are adjustablyconfigured by higher layers for the corresponding channel andtransmission mode. Thus, the power control parameters (1215) areconfigured by higher layers for the corresponding channel andtransmission mode. The term PL is the downlink path loss estimatecalculated in the UE for serving cell c in dB. This formula protects theserving cell from the interference of the sidelink communications. Inspecial situations where this protection is not needed, the UE can beinstructed by the eNB to use the maximum UE output power through D2Dgrant (i.e., TPC=1).

In Long Term Evolution Inter-Cell Interference Coordination, a proactiveindicator, known as the “High Interference Indicator,” can be sent by anEvolved Node B (eNodeB or eNB) to its neighboring Evolved Node B toinform them that it will, in the near future, schedule uplinktransmissions by one or more cell-edge user equipment in certain partsof the bandwidth, and therefore that high interference might occur inthose frequency regions. As illustrated in FIG. 2A, X2 is the name ofthe interface that connects one Evolved Node B to another Evolved NodeB. S1 is the interface for the communications between Evolved Node B anda Mobility Management Entity (MME).

Neighboring cells may then take this information into consideration inscheduling their own UEs to limit the interference impact. This can beachieved either by deciding not to schedule their own cell-edge userequipment in that part of the bandwidth and only considering theallocation of those resources for cell-center UEs requiring lesstransmission power, or by not scheduling any UE at all in the relevantResource Blocks (RBs).

The High Interference Indicator (HII) is comprised of a bitmap with onebit per Resource Block, and, like the Overload Indicator (OI), is notsent more often than every 20 milliseconds. The High InterferenceIndicator bitmap is addressed to specific neighbor Evolved Node Bs. Onthe other hand, the Overload Indicator, being a reactive indicator, canbe exchanged over an X2 application protocol interface to indicatephysical layer measurements of the average uplink interference plusthermal noise for each Resource Block. The Overload Indicator can takethree values, expressing low, medium, and high levels of interferenceplus noise. In order to avoid excessive signaling load, it cannot beupdated more often than every 20 milliseconds.

SUMMARY OF INVENTION

In some embodiments, the invention may be a base station (e.g. a basestation device) in a wireless communication network, comprising multiplebase stations. Here each base station can be configured to send andreceive communications to another base station in the wirelesscommunication network, as well as to a first plurality of userequipment. In this embodiment, a second plurality of user equipment maybe created by each of the user equipment in the first plurality of userequipment that has formed the device to device communication. The basestation may be configured to perform various functions, such as tocollect statistical information on active device to devicecommunications. The base station may also be configured to send amessage to a second base station in the wireless communication network.This message may comprise this statistical information on active deviceto device communications. This message may also enable the base stationsto use this statistical information to determine an interference levelfrom device to device communications.

In an alternative embodiment, the invention may be a user equipment(e.g. a user equipment device) receiving messages from the base station.The user equipment is configured to implement the steps of: receiving amessage comprising statistical information on active device to devicelinks from a base station in a wireless communication network. Accordingto this method, the user equipment will; determine whether or not toconnect with another user equipment by using this statisticalinformation to calculate an interference level, which is usable indetermining transmit power for device to device communications.

In another embodiment, the invention may comprise a base station in awireless communication network. This wireless communication network willtypically comprise multiple base stations. Here each base station isable to send and receive communications to another base station in thewireless communication network and also to a first plurality of userequipment. Here a second plurality of user equipment is created by eachof the user equipment in the first plurality of user equipment that hasformed the device to device communications. In this embodiment, the basestation is configured to: send power control parameters to a userequipment in the second plurality of user equipment. These power controlparameters are usable in this user equipment in the second plurality ofuser equipment to determine a power control function, “PD”. This powercontrol function is used to determine a calculated value of transmitpower. This calculated value is selected from the group consisting of:the power control function; and a conventional power control value whosepath loss is the path loss to a first base station.

In an alternative embodiment, the invention may comprise user equipmentconfigured to implement steps of: receiving power control parametersfrom a first base station in a wireless communication network. The userequipment is configured to use the power control parameters to determinea power control function, “P_(D)”. The user equipment thereafter usesthis power control function to determine a calculated value of transmitpower. This calculated value may be selected from the group consistingof: the power control function; and a conventional power control valuewhose path loss is the path loss to the first base station.

In another embodiment, the invention may comprise a location-estimationcomponent. This location-estimation component may comprise aninterconnection with a self-tracking component, and a signal-detectioncomponent. This interconnection is configured to enable provision ofdata to the location-estimation component. The location-estimationcomponent is configured to estimate location information based on dataprovided by the self-tracking component, and the signal-detectioncomponent. Here the location information may be selected from the groupconsisting of: geographic coordinates of one or more target transmitterswhich broadcast signals that can be detected by the signal-detectioncomponent; a localization-related parameter for such geographiccoordinates; and a direction the location-estimation component wouldhave to go to approach the one or more target transmitters. In thisembodiment, the self-tracking component may comprise sensors configuredto perform measurements of location information of thelocation-estimation component. The signal-detection component may beconfigured to detect one or more signal properties at locations selectedfrom among those where the self-tracking component performs ameasurement and the signal properties contain distance informationbetween the location-estimation component and the one or more targettransmitters. In another embodiment, the invention may comprise anon-transitory computer readable medium storing instructions thereon.These instructions may comprise instructions, that when implemented on acomputer, enable the computer to receive proximity information of one ormore target transmitters within a plurality of target transmitters froma localization module. These instructions may further enable thecomputer to implement steps of a) reading or storing information relatedto the one or more target transmitters from a storage component thatcomprises non-transitory computer readable memory; b) reading andprocessing information of the one or more target transmitters using auser-interface component; c) downloading or uploading informationrelated to target transmitters from the Internet using an optionalInternet access component; d) sending the information of the targettransmitters to a proximity-display module for display. Here thelocalization module is capable of estimating location information of theone or more target transmitters within the plurality of targettransmitters and, and may comprise a self-tracking component, asignal-detection component, and a location-estimation component. In thisembodiment, the location-estimation component may be configured toestimate location information based on data provided by theself-tracking component, and the signal-detection component. Theseinstructions are used to build a proximity system. Here the locationinformation may be selected from the group consisting of: geographiccoordinates of the one or more target transmitters who broadcast signalsthat were detected by the signal-detection component; alocalization-related parameter for such geographic coordinates; and adirection the localization module would have to go to approach the oneor more target transmitters. In this embodiment, the self-trackingcomponent, the signal-detection component and the location-estimationcomponent are interconnected so as to enable provision of data to thelocation-estimation component. The instructions may further enable thecomputer to implement steps of:

-   -   using an Internet connection between said computer and one or        more remote servers to upload material of a target transmitter        in the plurality of target transmitters to said one or more        remote servers; and    -   manage the proximity information of each verified target        transmitter to the said one or more remote servers,        wherein said material can be used to verify ownership of a        target transmitter in the plurality of target transmitters that        once verified becomes a verified target transmitter.

Technical Problem

There is a need for greater efficiency and interference coordination indevice to device communications, which can enable far greater automatedinterconnectivity between devices in proximity to each other. This needis for a simple device and method that provides a power control functionfor determining the minimum power necessary transmit a signal forreliable sidelink data communications (communications between devices);rather than simply the conventional power value, i.e. the power controlvalue whose path loss is the path loss to the serving station; and forimproved interference coordination for sidelink communications.

Despite the obvious potential benefits and revenue opportunities,competition is present from existing similar proximity-based services tosome extent through Wireless Fidelity (Wi-Fi), and/or Bluetoothapplications. Examples of proximity-based services are Digital LivingNetwork Alliance (DLNA) and Universal Plug and Play (UPP).

Digital Living Network Alliance and Universal Plug and Play enable thediscovery of other devices of interest, after which Internet Protocol(IP) level data communication is made possible between the devices.Digital Living Network Alliance and Universal Plug and Play, however,only work within the confines of a single wireless local area network(WLAN) or a single local area network (LAN). These have, however, seenlimited mainstream adoption up to now, which may be due to the fact thatthese existing solutions suffer a number of limitations including rangeand scalability issues; privacy concerns, as well as a huge drain onbattery resources, which limit their use by consumers.

Ultimately, Long Term Evolution Device-to-Device (LTED2D), which is alsocalled “sidelink” communications in 3rd Generation Partnership Project,provides a universal platform for proximity services. Long TermEvolution Device-to-Device opens the potential for a host of new serviceopportunities, while also achieving significant performance andefficiency benefits on the Long Term Evolution (LTE) networks.

From what is known in this field, there is a need for a system andmethods achieving low-complexity interference coordination andlocalization techniques for proximity services.

Solution To Problem

The solution disclosed herein defines a new generic framework tocoordinate the communications between the proximity devices and the basestations so that the interferences generated by the proximity devicesare effectively controlled to achieve high network peroformance.

This solution of interference controls goes beyond first levelinterferences addressed in current technology and addresses second levelinterferences to enable high capacity D2D communications.

The generic framework consists of distributed mode selection, powercontrol, and inter-cell interference coordination to enable scalabledirect communications between devices in proximity and localization ofdevices in proximity to provide more efficient services.

This generic framework has the potential to maximize the number ofsimultaneous active device to device links, thus maximizing networkfrequency reuse and network throughput.

This framework provides a new and effective method to assure quality ofservice to both cellular UEs and Device to Device UEs.

This generic framework includes three key innovative technologies togreatly enhance the provision of proximity-based services in mobilewireless networks. These key innovative technologies include: A new airinterface consisting of power control and interference coordination thatis implemented in Long Term Evolution-A cellular networks or likenetworks for scalable Device to Device communications and interferencecontrol; and an autonomous localization technique for finding wirelesstransmitters in proximity to provide efficient proximity services.

These key innovative technologies, while forming a holistic frameworkfor proximity-based services, may be implemented independently inpractice, wherever it is necessary or convenient to do so.

Advantageous Effects of Invention

To enhance the efficiency of proximity services, a preferred embodimentintroduces an autonomous location scheme to enable a device to locateother wireless devices in proximity.

This autonomous location scheme enables the device to approach theadjacent devices in proximity and communicate with lesser transmissionpower, which effectively reduces the second level interference to thenetwork.

The advanced technology disclosed herein may be implemented in any formof device-to-device direct communications. This means that any type ofproximity-based services with direct communications between UEs are ableto use it. It can be integrated in currently technologies as in, forexample: Wi-Fi-direct; Device to Device communications in cellularnetworks, including Machine-to-Machine (M2M) communications, and so on.

BRIEF DESCRIPTION OF DRAWINGS

The drawings illustrate preferred embodiments of the methods andapparatus for enabling proximity services in mobile networks accordingto the disclosure. The reference numbers in the drawings are usedconsistently throughout. New reference numbers in FIG. 2A and FIG. 2Bare given the 200 series numbers. Similarly, new reference numbers ineach succeeding drawing are given a corresponding series numberbeginning with the figure number.

FIG. 1 is an illustration of logic interfaces in a network known in theprior art.

FIG. 2A is an illustration of logic interfaces of network known in theprior art.

FIG. 2B is an illustration of a base station (eNB) and cells known inthe prior art.

FIG. 3A is the first part of a table of load information describing amessage sent by an Evolved Node B to neighboring Evolved Node Bs totransfer load and interference co-ordination information.

FIG. 3B is the second part of the table of load information describing amessage sent by an Evolved Node B to neighboring Evolved Node Bs totransfer load and interference co-ordination information.

FIG. 3C is the third part of the table of load information describing amessage sent by an Evolved Node B to neighboring Evolved Node Bs totransfer load and interference co-ordination information.

FIG. 4A is the first part of a table showing information related tosidelink communications that is carried in the load information betweenEvolved Node Bs.

FIG. 4B is the second part of the table showing information related tosidelink communications that is carried in the load information betweenEvolved Node Bs.

FIG. 4C is the third part of the table showing information related tosidelink communications that is carried in the load information betweenEvolved Node Bs.

FIG. 5 is a block diagram of a localization module.

FIG. 6A illustrates a measurement result by a self-tracking component inuser equipment.

FIG. 6B illustrates implementation of the localization module in amobile device to locate target transmitters in proximity where themobile device is not connected to the Internet.

FIG. 7 illustrates implementation of the localization module in a mobiledevice to locate target transmitters in proximity where the mobiledevice is connected to the Internet and a remote sever.

FIG. 8 is a block diagram of a proximity system in a mobile device.

FIG. 9 is a block diagram illustrating a proximity description module.

FIG. 10 is a block diagram illustrating functions of the proximityadvertisement module.

FIG. 11 illustrates a means for estimating the number of active deviceto device links per unit area.

FIG. 12 illustrates an example role of the implementation of the novelsignal steps and procedures between a device to device pair and itsserving base stations.

FIG. 13 is a pictorial representation of the signaling flow of anembodiment of the invention with the flow for base stations shown on theleft and the flow for device to device pairings shown on the right.

FIG. 14 illustrates simulation parameters and performance of theimplementation in a multi-cell cellular network.

DESCRIPTION OF EMBODIMENTS

In the following description, reference is made to the accompanyingdrawings, which form a part hereof and which illustrate severalembodiments of the present invention. The drawings and the preferredembodiments of the invention are presented with the understanding thatthe present invention is susceptible of embodiments in many differentforms and, therefore, other embodiments may be utilized and structural,and operational changes may be made, without departing from the scope ofthe present invention.

FIG. 1 illustrates four types of elements in a radio access network: adevice in proximity, also referred to as user equipment (105), a primaryuser equipment, which is user equipment that communicates directly withthe network, and a base station (210), also known as eNodeB (120), whichmanages a cell (130) or several cells. FIG. 2B illustrates an eNodeB andcell (205). The base station (210) is called an access point in Wi-Fisystems and is called an eNodeB in 3GPP network infrastructure. Eachbase station (210) is responsible for radio transmission and receptionin one or more cells to or from the user equipment. Each access point,which is a conceptual point, is associated with one specific cell, andit is an end point of a radio link between the UE and radio accessnetwork.

The core network, also illustrated in FIG. 2A, is the medium to connectto the Internet (125) and a remote server (710), shown in FIG. 7, or oneor more remote servers (935), shown in FIG. 9. These remote servers mayinclude one or more databases, shown in FIG. 9 and FIG. 10. A servergroup (one or more remote servers (935)) preferably includes multipleservers and data bases in the core network, which may provide servicestogether and may communicate with each other for functional purposes.

An example of a remote server (710) or one or more remote servers (935)accessed through the Internet (125) is an advertisement server. Theadvertisement server stores in non-transitory computer readable memoryadvertisements used in online marketing and delivers theseadvertisements to mobile terminals, such as for example websitevisitors. Website users typically include mobile users of user equipment(105), such as, for example, laptops, desktops, tablets and smartphones.

As shown in FIG. 2A, the core network may also serve as the X2 and S1interfaces between the base stations. S1 and X2 are known interfaces in3GPP network nodes: The S1 interface separates E-UTRAN and EPC; and theX2 interface is the interface between base stations (eNBs).

Each base station (210) is a component entity that controls thesignaling of the UE and routes traffic between primary UEs and the corenetwork. The wireless links for primary UEs and Device to Device UEsgenerate the two levels of interferences to each other.

The primary UEs communicate to the network directly. For example, in3GPP, the primary UE is user equipment (105) that communicates directlyto the eNodeBs. In Wi-Fi, the primary user equipment (135) a devicesthat communicates directly to a Wi-Fi access point. The devices inproximity are referred to herein as Device to Device (D2D) userequipment, user equipment (105) or proximity devices. A device to devicepair involves two devices, that is for example, a first user equipmentthat communicates with a second user equipment. The communications of aD2D pair may also be called sidelink communications. Note that Device toDevice communications may be present without the existence of primaryUEs or base stations.

A preferred embodiment disclosed herein includes a set of technologiesto determine mode selection and transmission power and interferencecoordination for Device to Device communications.

Mode selection refers to procedures to decide if a pair of devices inproximity should communicate directly with each other or through thebase stations (210). These technologies work together to coordinate twolevels of interferences generated by Device to Device communications toachieve the optimal network performance.

The set of technologies preferably enables two devices in proximity ofeach other to locate each other and track them so that they are betterable to move closer to each other. Such tracking and knowledge ofproximity enables the two devices to employ a higher data rate transferwith lower interference to the network, which further improves networkperformance.

Information Elements

In a preferred embodiment, the network, e.g. an access point, a basestation, or a group of base stations, keeps the track of stasticalinformation relating to active device to device links in its servingarea (one or more cells). The network sends to a mobile device aparameter, preferably a set of parameters or signalings, named Device toDevice Information Element (D2DIE), that carries the statisticalinformation of existing active device to device links. The Device toDevice Information Element may be used to calculate, i.e., derive thetolerable mutual interference among potential device to device links ina certain area.

Therefore, in one embodiment of the invention, a base station apparatusis configured to send to a mobile device the D2DIE, that carries thestatistical information of existing active device to device links. TheD2DIE may be used to calculate, i.e., derive the tolerable mutualinterference among potential device to device links in a certain area.

In one embodiment of the invention, a user equipment is configured toreceive the D2DIE, that carries the statistical information of existingactive device to device links, from a base station. The D2DIE may beused by the user equipment to calculate, i.e., derive the tolerablemutual interference among potential device to device links in a certainarea.

One example of the parameter that is carried in a Device to DeviceInformation Element is the density or number of existing active deviceto device links in a certain area, e.g. cells. The density may then beused to derive the potential interference among different device todevice links in the area. The higher the number of device to devicelinks, the higher the mutual interference that may be expected to existin the area.

A second example of the parameter is an indicator of Device to Deviceinterference in the cell, where 1 means too much interference betweendevice to device links and 0 means negligible interference among deviceto device links. Or the indicator can be of several, e.g. three, levels,where each level indicates the strength of interferences among device todevice links. A bitmap can be used to indicate the correspondinginterference levels on all resource blocks of interest. For example thebitmap has the format BIT STRING (1 . . . 110, . . . ); and wherein theSemantics description is: Each position in the bitmap represents aPhysical Resource Block (first bit=PRB 0 and so on), for which value“'1” indicates ‘high interference sensitivity’ and value “0” indicates‘low interference sensitivity’.

Preferably, the Device to Device Information Element is used to controlthe inteference among different device to device links. The Device toDevice Information Element may also be used to prevent too many deviceto device links to be admitted in the network. For example, when theDevice to Device Information Element is carried in the discoverymessages, it can help determine whether or not an active status for theuser equipment will be in sidelink mode.

The transmission of the Device to Device Information Element may be cellspecific or may be broadcasted by the network. In addition, thetransmission of Device to Device Information Element may beuser-equipment specific and sent to the user equipment (105) usingdedicated resources.

In one example of transmission, an Evolved Node B broadcasts thisparameter to a plurality of user equipment within its cell. In anotherexample, several Evolved Node Bs may jointly determine this parameterand send it to a particular user equipment.

In another example of transmission, existing device to device linksestimate the average amount of interference that has already existedamong themselves and broadcast this parameter so that new device todevice links can estimate the interference if they start datacommunications.

In a third example of transmission, the Device to Device InformationElement is carried in the discovery messages from eNodeB to the D2D UEwhen a new device to device pair is established.

A mobile device is configured to receive the D2DIE and may use thestatistical information in the D2DIE in its D2D communictions. Forexample, the statistical information may be used by the mobile device todetermine whether or not to connect with another user equipment. Foranother example, the statistical information may also be used tocalculate an interference level, which is usable in determining transmitpower for device to device communications.

Preferably, base station (210) communicates with adjacent base stations,sending one or more parameters or signalings, named Device to DeviceInformation Element 2 (D2DIE2), that includeds or carries thestatistical information of the active device to device links in its ownserving area.

There, a base station apparatus is configured to send to adjacent basestations one or more parameters or signalings, named D2DIE2, thatincludeds or carries the statistical information of the active device todevice links in its own serving area. D2DIE2 may be used by adjacentbase stations to determine an interference level from device to devicecommunications.

A base station apparatus is configured to receive one or more parametersor signalings, named D2DIE2, that includeds or carries the statisticalinformation of the active device to device links, from an adjacent basestation. Said base station may use D2DIE2 to determine an interferencelevel from device to device communications.

Thus, in a preferred method the wireless communication network (100)includes multiple base stations. The preferred method is utilizable in awireless communication network. Each base station (210) is able to sendand receive communications (110) to another base station in the wirelesscommunication network. Each base station (210) is able to send andreceive communications (110) and to a first plurality of user equipment.This first plurality of user equipment represents the user equipment(105) within the area served by the wireless communication network(100). A second plurality of user equipment is created by each of saiduser equipment in the first plurality of user equipment that has formeda pairing with another user equipment. For example, the second pluralityof user equipment may be two mobile devices that are in sidelinkcommunications. Each such pairing defined as a device to device link. Inthe method the base station (210) implements steps of: controlling amessage from a first base station in the wireless communication networkto user equipment (105) in the first plurality of user equipment, themessage comprising statistical information on active device to devicelinks; and enabling each user equipment (105) in the first plurality ofuser equipment to determine whether or not to connect with another userequipment in the first plurality of user equipment based using thestatistical information to calculate an interference level for a newdevice to device link (140). The calculations are performed inaccordance with the disclosure herein.

The statistical information includes at least one of: the density ofactive device to device links; and a high interference indicator fordevice to device communications; wherein said statistical information isusable by each user equipment (105) in the first plurality of userequipment to determine a projected interference level for a new deviceto device link (140).

The method may also include a steps of: sending the statisticalinformation from the first base station in the wireless communicationnetwork to a second base station in the wireless communication network;forming the high interference indicator for device to devicecommunications to include a binary indicator where 1 means highinterference and 0 means negligible interference; and forming the highinterference indicator for device to device communications to includemultiple levels of interference power. The high interference indicatormay be obtained by adding one bit into the existing High InterferenceIndicator of Long Term Evolution-A specification and this one bit isused to indicate whether or not the High Interference Indicator is fromthe sidelink communications.

Device to Device Information Element 2 may be used to derive a tolerablemutual interference from device to device links in areas served by theadjacent base stations.

A first example of a parameter that may be carried in Device to DeviceInformation Element 2 is the density or number of active device todevice links in the serving area of the base station, i.e. those devicesthat the base station or cell serves. The Device to Device InformationElement 2 can be used to derive the potential interference from thesedevice to device links to the device to device links in adjacent cells.The higher the number of device to device links, the higher theinterference may be expected.

A second example of a parameter that may be carried in Device to DeviceInformation Element 2 is a high Device to Device interference indicatorin a cellular area, where 1 means too much interference between deviceto device links and 0 means negligible interference among device todevice links. Alternatively, the indicator may be one of several levels,e.g. three levels, where each level indicates the strength ofinterferences among device to device links. A bitmap can be used toindicate the corresponding interference levels on all resource blocks ofinterest. For example the bitmap has the format BIT STRING (1 . . . 110,. . . ); and wherein the Semantics description is: Each position in thebitmap represents a Physical Resource Block (first bit=PRB 0 and so on),for which value “'1” indicates ‘high interference sensitivity’ and value“0” indicates ‘low interference sensitivity’.

Device to Device Information Element 2 is preferably exchanged on logicinterfaces such as X2 or S1 interfaces, as shown in FIG. 2A.

Preferably, the network broadcasts a parameter or signaling, namedDevice to Base Stations Information Element (D2DBSIE), that carriesstastical information of the tolerable performance loss of the primaryUEs.

The network provides data on the maximum amount of interference that canbe tolerated by primary user equipment (135), i.e. user equipment (105)directly connecting to the network, using the Device to Base StationsInformation Element. For example, the parameter broadcast by the networkmay be a Signal-to-Interference-plus-Noise Ratio loss in decibels (dB)that can be tolerated by cellular users in 3GPP cellular networks.

Another example of the Device to Base Stations Information Element isthe throughput loss that can be tolerated by the UEs connected directlyto the base station.

A third example of the Device to Base Stations Information Element is aone bit indicator, where 1 means additional Device to Devicecommunications are allowed and the resulting interference to the networkis negligible; and 0 means additonal Device to Device communicationswill create too much interference and new Device to Devicecommunications should not be allowed.

A forth example of the Device to Base Stations Information Element is anN-state indicator, which means K of the N levels of the interferencegenerated by the Device to Device communications can be tolerated. Abitmap can be used to send Device to Base Stations Information Elementto indicate the corresponding tolerable interference levels on allresource blocks of interest.

Novel Transmission Power Control Function

A novel feature of a preferred embodiment disclosed herein is the powercontrol for the transmission of sidelink communications to be theminimum of P_(D) and the conventional power control. As introduced inthe BACKGROUND section, supra, in the conventional power control, pathloss in the power control formula is the path loss from the userequipment to the serving cell and protects the serving cell from highinterference from the sidelink communications. The power controlfunction, P_(D) is used to determine the minimum transmit powernecessary for reliable data communications of the sidelink. Selectingthe minimum of P_(D) and the conventional power control as thetransmission power, ensures a minmum transmission power for sidelinkcommunications, which reduces the overall second-level interference andenables more D2D links to communiate at the same time.

Thus, in a preferred method utilizable in a wireless communicationnetwork (100), the wireless communication network (100) comprisingmultiple base stations, wherein each base station (210) is able to sendand receive communications (110) to another base station in the wirelesscommunication network (100) and to a first plurality of user equipment,wherein a second plurality of user equipment is created by each of saiduser equipment (105) in the first plurality of user equipment that hasformed a pairing with another user equipment, each such pairing definedas a device to device link (140), the method comprising the step of:sending power control parameters (1215) from a first base station in thewireless communication network (100) to the second plurality of userequipment, the power control parameters (1215) usable in each userequipment (105) in the second plurality user equipment to determine apower control function, P_(D), and thereafter use the power controlfunction to determine a calculated value, the calculated value selectedfrom the group consisting of: a minimum transmit power for reliable datacommunications of the device to device link (140); and a conventionalpower control value whose path loss is the path loss to the first basestation.

This preferred method utilizable in a wireless communication network(100) may further include a step of sending, from the first base stationto each user equipment (105) in the second plurality user equipment,information selected from the group consisting of a higher-layerparameter for a channel and transmission mode, a modulation and codingscheme, cumulative transmit power control command, and a path lossnumber between user equipment (105) forming the device to device link(140); and enabling said user equipment (105) to use said information torefine the determination of the power control function prior to usingthe power control function to determine the calculated value. The term“higher-layer parameter” as used herein is a term well known in the artand defined in the specification 3GPP TS 36.213 V12.7.0 (2015-09),Release 12, which is hereby incorporated by reference herein.

Thus, to implement the method, in one embodiment of the invention: abase station apparatus is configured to send power control parameters(1215) to the second plurality of user equipment, the power controlparameters (1215) usable in each user equipment (105) in the secondplurality user equipment to determine a power control function, P_(D),and thereafter use the power control function to determine a calculatedvalue of transmit power, the calculated value selected from the groupconsisting of: a minimum transmit power for reliable data communicationsof the device to device link (140); and a conventional power controlvalue whose path loss is the path loss to the first base station.

The bsae station apparatus may be configured to further send to a userequipment (105) in the second plurality user equipment, informationselected from the group consisting of a higher-layer parameter for achannel and transmission mode, a modulation and coding scheme,cumulative transmit power control command, and a path loss numberbetween user equipment (105) forming the device to device link (140).Said user equipment (105) may use said information to refine thedetermination of the power control function prior to using the powercontrol function to determine the calculated value of the transmitpower.

To implement the method, in another embodiment of the invention: a userequipment is configured to receive power control parameters (1215) froma base station and use the power control parameters (1215) to determinea power control function, P_(D), and thereafter use the power controlfunction to determine a calculated value of transmit power. Thecalculated value of transmit power is selected from the group consistingof: the power control function; and a conventional power control valuewhose path loss is the path loss to the first base station.

The user equipment may be configured to further receive from from a basestation information selected from the group consisting of a higher-layerparameter for a channel and transmission mode, a modulation and codingscheme, cumulative transmit power control command, and a path lossnumber between user equipment (105) forming the device to device link(140). The user equipment (105) may use said information to refine thedetermination of the power control function prior to using the powercontrol function to determine the calculated value of the transmitpower.

In a first example, the transmit power required for reliable datatransfer in sidelink communications is determined. PSSCH is the datachannel for Device to Device communications (PSSCH is short for physicalsidelink control channel), also termed “sidelink communications.”

Sidelink transmission mode 1 is also referred to as “Scheduled ResourceAllocation” because access to the sidelink resources is driven by theeNodeB and not the user equipment (105).

In mode 1, when the measured transmit power is too low, the base station(210) sends a special command to request an increase in the transmitpower. And when the measured power is too strong, the base station (210)sends another command requesting a decrease in the power. This is ameans for the transmitter to dynamically change its output power. Thiskind of power control mechanism is often called “Closed Loop PowerControl” and the special command being used for power control is calledTransmit Power Control (TPC) command.

For mode 1 and a PSSCH period of i, the user equipment (105) transmitpower, P_(PSSCH,) when the Transmit Power Control command field inconfigured sidelink grant for P_(SSCH) period i is set to 1, is given bythe following:

$P_{PSSCH} = {\min{\begin{Bmatrix}P_{{CMAX},{PSSCH}} \\{{10{\log_{10}\left( M_{PSSCH} \right)}} + P_{{O\;\_\;{PSSCH}},1} + {\alpha_{{PSSCH},1} \cdot {PL}}} \\P_{D}\end{Bmatrix}\lbrack{dBm}\rbrack}}$

In the above formula, “min” means take the minimum value of the threeterms in the parentheses. M_(PSSCH) is the transmission bandwidth of thePSSCH resource assignment expressed in number of resource blocks; PL isthe path loss where PL=PLC, where PL_(c) is the downlink path lossestimate calculated in the user equipment (105) for serving cell “c”, indB; and the conventional power control ismin{P _(CMAX,PSSCH), 10 log₁₀(M _(PSCCH))+P _(O) _(_)_(PSSCH,1)+α_(PSCCH,1) ·PL}where P_(O) _(_) ^(PSSCH,1) and ∀_(PSSCH,1) are provided by higher layerparameters p0-r12 and alpha-r12, respectively, and that are associatedwith the corresponding PSSCH resource configuration.

A second example uses sidelink transmission mode 2. Mode 2 is alsoreferred to as User Equipment Autonomous Resource Selection: In mode 2,the user equipment (105) transmitting Device to Device data does notneed to be connected to the eNodeB because the user equipment (105)selects autonomously and randomly the resources within the PSSCH pool totransmit the Sidelink Control Information block. In this second example,the user equipment transmit power P_(PSSCH) is given by

$P_{PSSCH} = {\min{\begin{Bmatrix}P_{{CMAX},{PSSCH}} \\{{10{\log_{10}\left( M_{PSSCH} \right)}} + P_{{O\;\_\;{PSSCH}},2} + {\alpha_{{PSSCH},2} \cdot {PL}}} \\P_{D}\end{Bmatrix}\lbrack{dBm}\rbrack}}$

In this second formula, P_(CMAX,PSSCH) is the maximum UE output power.PSSCH is short for physical sidelink shared channel; M_(PSSCH) is thebandwidth of the PSSCH resource assignment expressed in number ofresource blocks; PL is the path loss where PL=PLC, where PLC is thedownlink path loss estimate calculated in the user equipment (105) forserving cell “c”, in dB. The conventional power value ismin{P _(CMAX,PSSCH), 10 log₁₀(M _(PSCCH))+P _(O) _(_)_(PSSCH,2)+α_(PSCCH,2) ·PL}where P_(O) _(_) ^(PSSCH,2) and ∀_(PSSCH,2) are provided by higher layerparameters p0-r12 and alpha-r12, respectively, and that are associatedwith the corresponding PSSCH resource configuration.

In a third example, the transmit power required for reliable controlinformation transfer in sidelink communications is determined. PSCCH isthe control information channel for Device to Device communications,also termed “sidelink communications.” For Device to Devicecommunications, using the PSCCH chanel in sidelink transmission mode 1and a PSCCH period of i, the user equipment transmit power, P_(PSSCH),when the Transmit Power Control command field in configured sidelinkgrant for P_(SCCH) period i is set to 1, is given by the following:

$P_{PSCCH} = {\min{\begin{Bmatrix}P_{{CMAX},{PSCCH}} \\{{10\;{\log_{10}\left( M_{PSCCH} \right)}} + P_{{O\;\_\;{PSCCH}},1} + {\alpha_{{PSCCH},1} \cdot {PL}}} \\P_{D}\end{Bmatrix}\lbrack{dBm}\rbrack}}$

In this third formula, “min” means take the minimum value of the termsin parentheses. P_(CMAX,PSCCH) is the maximum UE power for the controlinformation channel; M_(PSCCH)=1; PL=PL_(c), where PL_(c) is thedownlink path loss estimate calculated for the user equipment (105) forserving cell “C”, in dB; and the conventional power value ismin {P _(CMAX,PSCCH),10 log₁₀(M _(PSCCH))+P _(O) _(_)_(PSCCH,1)+α_(pSCCH,1) ·PL}

In a fourth example using the control information channel for Device toDevice communications in sidelink transmission mode 2, the userequipment transmit power, P_(PSCCH), is given by

$P_{PSCCH} = {\min{\begin{Bmatrix}P_{{CMAX},{PSCCH}} \\{{10\;{\log_{10}\left( M_{PSCCH} \right)}} + P_{{O\;\_\;{PSCCH}},2} + {\alpha_{{PSCCH},2} \cdot {PL}}} \\P_{D}\end{Bmatrix}\lbrack{dBm}\rbrack}}$

In this third formula, P_(CMAX,PSCCH) is the maximum power limit for thetransmitter user equipment; M_(PSCCH)=1 and PL=PL_(c) where PL_(c) isthe downlink path loss estimate calculated in the user equipment (105)for serving cell “C” in dB; and the conventional power value ismin{P _(CMAX,PSSCH),10 log₁₀(M _(PSCCH))+P _(O) _(_)_(PSSCH,1)+α_(PSCCH,1) ·PL}where, P_(O) _(_) _(PSCCH,2) and ∀_(PSCCH,2) are provided by higherlayer parameters p0-r12 and alpha-r12, respectively, and that areassociated with the corresponding PSCCH resource configuration.

In the examples given above, the newly defined power control function,P_(D), for sidelink communications determines the necessary transmitpower for reliable data and control information communications of thesidelink. P_(D) does not necessarily have the same value in eachformula. Seven examples below, designated a.-g., illustrate sevendifferent situations for setting the value of P_(D):

a. P_(D)::=P_(D)::={a₁, a₂, . . . , a_(k)} dBm, e.g. P_(D)::={−30, −29,. . . 22, 23} dBm, i.e., an integer in decibel-milliwatts (dBm) between−30 and 23. The value to be used is configured by higher layerparameters or preconfigured in the system, e.g. stored in a SIM card;

b. For PSSCH or PSCCH,P _(D)=10 log₁₀(M _(D2D))+P _(O) _(_) _(D2D)[dBm]Where M_(D2D) denotes the D2D transmission bandwidth in number of PRBsfor the corresponding channel, e.g. PSSCH or PSCCH. P_(O) _(_) _(D2D) isthe adjustable power control parameter that is configured by higherlayers for the corresponding channel and transmission mode. P_(O) _(_)_(D2D) may also be preconfigured in the system, e.g. stored in a SIMcard.

c. For when the sidelink is experiencing unicast or relay communicationsbetween two user equipment in proximity, the power control function, Ppfor PSSCH or PSCCH is calculated as,P _(D)=10 log₁₀(M _(D2D))+P _(O) _(_) _(D2D)+α_(D2D) ·PL _(s)[dBm]

M_(D2D) denotes the D2D transmission bandwidth in number of PRBs for thecorresponding channel, e.g. PSSCH or PSCCH. P_(O) _(_) _(D2D) andα_(D2D) are the power control parameters (1215) that are adjustablyconfigured by higher layers for the corresponding channel andtransmission mode. P_(O) _(_) _(D2D) and α_(D2D) may also bepreconfigured in the network, e.g., stored in a SIM card. PL_(S) is thepath loss estimate in dB calculated in the user equipment (105) for thelink between the two user equipment devices of the sidelink. Thus, thepower control parameters (1215) may be configured by higher layers forthe corresponding channel and transmission mode or are preconfigured inthe the wireless communication network (100).

d. For when the user equipment (105) is in the groupcast or broadcastmode, i.e. one-to-many Proximity-Based Services Direct Communication,the power control function, P_(D), for PSSCH or PSCCH is given byP _(D)=10 log₁₀(M _(D2D))+P _(O) _(_) _(D2D)+α_(D2D) ·PL _(M)[dBm]where PL_(M) is a function of the path loss estimates in dB calculatedin the user equipment for the links between a first user equipment andother user equipment in the groupcast or broadcast. For example, assumea first user equipment plus N devices comprising other user equipment inthe groupcast mode receiving data from the first user equipment and thepath loss estimates from them to the first user equipment are PL₀, PL₁,. . . ,PL_(N-1) respectively. PL_(M) can be the maximum, minimum, ormedian, of these path loss estimates.

e. For when a mapping table of the density of active device to devicelinks is used, P_(D) is a function of the Device to Device InformationElement. For example, as illustrated in the following table ofenumerated values:

Density of device to device links (sidelink communications) P_(D) 1-3per cell 23 dBm 4-7 per cell 20 dBm Above 7 15 dBm

f. For the P_(D) in examples b.-d., P_(O) _(_) _(D2D), while provided byhigher layer parameters, is determined by the Device to DeviceInformation Element and given in the following table.

Density of device to device links (sidelink communications) P_(O)_D2D 1per cell 18 dBm 2 per cell 15 dBm Above 3 12 dBm

g. In this example, P_(D) is a function of Δ_(TF)(i), which isdetermined by the modulation and coding scheme used for the sidelinktransmission. For example, Δ_(TF)(i) is a function of: OCQI, which isthe number of Channel Quality Indicator/Pre-coding

Matrix Index (CQI/PMI) bits including cyclic redundancy check (CRC)bits; and N_(RE), which is the number of resource elements.

h. In this example, P_(D) is adjusted based on the accumulative TransmitPower Control commands received from the receiver of the sidelinkcommunications. With the accumulation of Transmit Power Controlcommands, each Transmit Power Control command signals a power steprelative to the previous level of the power control function, P_(D), forsidelink communications.

Novel Mode Selection

A novel feature of a preferred embodiment disclosed herein is modeselection of a device to device pair. Mode selection is a function ofDevice to Device Information Element or Device to Base StationsInformation Element. Mode selection is determined during device todevice pairing by an algorithm that performs calculations based oneither the Device to Device Information Element or the Device to BaseStations Information Element. Mode selection determines if the pairingshould be in device to device mode or not.

The algorithm for mode selection may be implemented after device todevice pairs have discovered each other. One example of the novel modeselection algorithm that can be implemented in Long Term Evolution-Ainfrastructure is one or several of the following procedures:

1. A pair of Device to Device User Equipment in proximity retrievesDevice to Device Information Element or Device to Base StationsInformation Element.

2. The device to device pair monitors the downlink reference signals toobtain the channel gain between the nearest access points and the deviceto device pair itself, which is already supported by existing standards.

3. The device to device pair may estimate the number of active device todevice links per unit area, calculate the transmission power, and decideits active status, i.e. whether in device to device mode or not.

4. In a network that allows the device to device link to decide its owncommunication mode, the device to device pair will communicate in deviceto device mode if the pair has decided to be in the device to devicemode; Otherwise, the device to device pair, either the transmitter orreceiver, will notify the serving access point of the pair's suggestionof whether or not the device to device pair should be in device todevice mode. After receiving the suggestion, the network may implement afuther calculation and then command the device to device pair tocommunicate in a certain mode, preferrably the mode suggested by thedevice to device pair itself.

Thus, in a preferred embodiment includes a method utilizable in awireless communication network (100), the wireless communication network(100) comprising multiple base stations, wherein each base station (210)is able to send and receive communications (110) to another base stationin the wireless communication network (100) and to a first plurality ofuser equipment, wherein a second plurality of user equipment is createdby each of said user equipment (105) in the first plurality of userequipment that has formed a pairing with another user equipment, eachsuch pairing defined as a device to device link (140). This includes thesteps of: enabling each user equipment (105) in any pairing to retrievea set of parameters defined as a device to device information element,said device to device information element used to calculate thetolerable mutual interference among potential device to device links;enabling each user equipment (105) in any pairing to retrieve parametersor signalings, named device to device information element 2, thatincludes statistical information of the active device to device linksserved by the base station (210) where by the pairing is made; enablingeach user equipment (105) in any pairing to monitor downlink referencesignals to obtain channel gain between the nearest access points and thedevice to device pair itself; enabling each user equipment (105) in anypairing to estimate the number of active device to device links per unitarea, calculate the transmission power, and decide said user equipment'sactive status of being in sidelink mode or not; enabling each userequipment (105) in any pairing to communicate in device to device modeif the pairing has decided to be in the device to device mode; enablingeach user equipment (105) in any pairing to notify an access point ofthe pair's suggestion of whether or not the device to device pair shouldbe in device to device mode and after receiving the suggestion; andcommanding the device to device pair to communicate in a certain mode,preferably the mode suggested by the device to device pair.

In another exemplary embodiment, the wireless communication network(100), e.g. an access point (Evolved Node B), may perform one or severalof the following procedures:

In the wireless communication network (100), each base station (210)keeps track of the density or number of active device to device links inits coverage area, which may be different in different areas or cells,to determine Device to Device Information Element.

If primary users exist, the base station (210) estimates the maximumamount of interference that can be tolerated or the maximum tolerableperformance loss, e.g. throughput loss, to determine Device to BaseStations Information Element.

The base station (210) broadcasts the two parameters to all userequipment (105), to device to device pairs, to a specific set of userequipment, or to a specific user equipment.

If and when the network performs the final mode decision for each deviceto device pair, the network preferably receives the mode suggestion fromdevice to device pairs and then sends a command back to the device todevice pair notifying the pair of the result, i.e. its mode decision.

Thus, the above exemplary embodiment, includes a method utilizable in awireless communication network (100), the wireless communication network(100) comprising multiple base stations, wherein each base station (210)is able to send and receive communications (110) to another base stationin the wireless communication network (100) and to a first plurality ofuser equipment, wherein a second plurality of user equipment is createdby each of said user equipment (105) in the first plurality of userequipment that has formed a pairing with another user equipment (105),each such pairing defined as a device to device link, the methodcomprising the steps of: enabling each base station (210) in thewireless communication network (100) to determine a device to deviceinformation element consisting of a set of parameters selected from thegroup consisting of: density or number of active device to device links;propagation constants related to a channel model; and a coverage areafor device to device links; enabling each base station (210) in thewireless communication network (100) to determine a device to basestations information element consisting of a set of parameters selectedfrom the group consisting of: a total amount of interference from thedevice to device links that is tolerable by the user equipment in anuplink; propagation constants related to a channel model; coverage areafor device to device links; and an average sum of channel gain ofexisting device to device links to the base stations; enabling each basestation (210) in the wireless communication network (100) to utilize thedevice to device information element and the device to base stationinformation element to determine a mode selection result for a device todevice paring; and sending the mode selection result to user equipment(105) in the first plurality of user equipment desiring to create thedevice to device pairing.

For the above exemplary embodiment, the device to base stationinformation element may be a high interference indicator for sidelinkcommunications in the wireless communication network. In addition whenthe high interference indicatory is present, then the above exemplaryembody further includes the step of sending the high interferenceindicator from a first base station to a second base station with anindication that in the near future, a potential transmission betweensidelink communications could be scheduled in certain parts of radioresources.

In one embodiment, the high interference indicator is obtained by addingone bit into the existing High Interference Indicator of Long TermEvolution-A specification and this one bit is used to indicate whetheror not the High Interference Indicator is from the sidelinkcommunications.

In another embodiment of the invention, a device to device link (140),base station (210), or the wireless communication network (100), maydecide if a device to device pair should be in the device to device modeor not by using the device to device information element or device tobase stations information element.

In one example of this embodiment, a potential device to device link mayestimate a lower bound and an upper bound of its transmission power forcommunication in the device to device mode. the lower bound is theminimum amount of transmissoin power needed to meet its ownsignal-to-interference-plus-noise ratio requirement. An example of thelower bound is P_(D), as is described above.

The upper bound of the transmission power is the maximum amount of poweruser equipment may use so that the interference generated to thenetwork, i.e. to the primary UEs and the other device to device links,is tolerable by them. An example of the upper bound is the existingpower control, i.e. the conventional power control, for sidelinkcommunications in Long Term Evolution-A in which the path loss is theposs loss for the serving cell.

For other instances, the upper bound can be estimated using a functionof the acceptalbe signal-to-interference-plus-noise ratio lossinformation in device to base stations information element and thedensity of device to device links in the surrounding area, which isavailable in the device to device information element.

The lower bound can be estimated using a function of thesignal-to-interference-plus-noise ratio requirement of the device todevice pair itself, the link gain between its transmitter and receiver,and the density of device to device links in its surrounding area. Ifthe upper bound is higher than the lower bound, the device to devicelink can be in active device to device communications, i.e. in thedevice to device mode, otherwise it must not be active.

Novel Inter-Cell Interference Coordination For Proximity Services

A novel feature of a preferred embodiment disclosed herein is a highinterference indicator for device to device communications betweenadjacent base stations. In implementing this feature, a device to deviceinformation element 2 is sent from one base station to adjacent basestations to indicate that in the near future, potential transmissionbetween sidelink (device to device) communications will be scheduled incertain parts of the radio resources, e.g. bandwidth, frequency divisionmultiplexing (FDM) symbols, or resource blocks, by the base station.

In another example of implementing this feature, a device to deviceinformation element 3 is sent from one user equipment of a device todevice pair to adjacent base stations to indicate that in the nearfuture, potential transmission between the sidelink (device to device)communications will be scheduled in certain parts of the radioresources, e.g. bandwidth, frequency division multiplexing (FDM)symbols, or resource blocks, by the device to device pair.

Thus, high interference might occur in those radio resources. Howeversince the interferences would be from sidelink communications, it islikely these interferences would not be as strong as those indicated bythe high interference indicator, since sidelink communiations have lesspriority. So, other Evolved Node Bs would consider it as lower priorityand would help in solving the interference issue if there were resourcesavailable. In addition, device to device communications may use theleast amount of power for transmission. The interference betweenadjacent cells can be negligible. So, no high interference may exist.

Therefore, in one embodiment of the invention, a user equipment isconfigured to send a message, named device to device information element3, that includes load and interference information of device to devicecommunications of the user equipment to a base station of an adjacentcell. This message indicate that in the near future, potentialtransmission between the sidelink (device to device) communications willbe scheduled in certain parts of the radio resources, e.g. bandwidth,frequency division multiplexing (FDM) symbols, or resource blocks, bythe device to device pair.

In an exemplary embodiment, one bit is added into the existing highinterference indicator, and this one bit is used to indicate whether thehigh interference indicator is from the sidelink communications or not.One example of the information element for high interference indicatoris given in the next paragraph, where the one bit is added to the frontof the existing High Interference Indicator.

For a high interference indicator whose presence is marked as mandatory(M), the information element type and reference is: BIT STRING (1, 1 . .. 110, . . . ), the semantics description is: The first bit representsif the high interference indicator is from device to deviceinterferences or not, for which value “1” indicates sidelinkcommunications and “0” otherwise. Each position of the remaining bits inthe bitmap represents a PResource Block (second bit=PResource Block 0and so on), for which value “'1” indicates ‘high interferencesensitivity’ and value “0” indicates ‘low interference sensitivity’. Themaximum number of Physical Resource Blocks is 110. The last bitrepresents if the High Interference Indicator is from device to deviceinterferences or not, for which value “1” indicates sidelinkcommunications and “0” otherwise.

In another exemplary embodiment, a dedicated information element isincluded in the load information in the 3GPP TS 36.423 specification(Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2Application Protocol (X2AP)) to indicate the potential high interferencefrom sidelink communications. An example of the load information isgiven in the tables of FIG. 3A, FIG. 3B, and FIG. 3C, which describes amessage sent by an Evolved Node B to neighboring Evolved Node Bs totransfer load and interference co-ordination information. Direction:Evolved Node B1 to Evolved Node B2.

An example of the Uplink High Interference Indication 2 (HighInterference Indicator 2) is defined as follows: For InformationElement/Group Name: High Interference Indicator 2; having an optionalpresence; where the Information Element type and reference is: BITSTRING (1 . . . 110, . . . ); and wherein the Semantics description is:Each position in the bitmap represents a Physical Resource Block (firstbit=PRB 0 and so on), for which value “'1” indicates ‘high interferencesensitivity’ and value “0” indicates ‘low interference sensitivity’;wherein the maximum number of Physical Resource Blocks is 110.

In another exemplary embodiment, the information related to sidelinkcommunications is carried in the load information between Evolved NodeBs. One example is given in the tables of FIG. 4A, FIG. 4B and FIG. 4C,which shows load information, where a new sidelink information isintroduced for this purpose. For example, Device to Device InformationElement 2 can be carried in the sidelink information. The detailedformat of the sidelink information is up to implementation. This messageis sent by an Evolved Node B to neighboring Evolved Node Bs to transferload and interference co-ordination information. Direction: Evolved NodeB1 to Evolved Node B2. The message of FIG. 4A, FIG. 4B and FIG. 4C issent by an Evolved Node B to neighboring Evolved Node Bs to transferload and interference co-ordination information.

In another embodiment of the invention, a logic interface like X2 iscreated between a mobile device in the sidelink communications toadjacent base stations or to adjacent devices in sidelinkcommunications. The logic interface is used to send device to deviceinformation element 3 of the sidelink communications to adjacent basestations or adjacent sidelinks. Device to device information element 3may carry load or interference information. A message that can be senton the logic interface is a high interference indicator for sidelinkcommunications, which is sent from a mobile device in the sidelinkcommunications to adjacent base stations or to adjacent devices insidelink communications. The high interference indicator is used toinform the adjacent base stations or adjacent devices that in the nearfuture, a potential transmission between sidelink (device to device)communications will be scheduled in certain parts of the radioresources, e.g. bandwidth, frequency division multiplexing symbols, orresource blocks, by the sidelink communications. Thus, high interferencemight occur in those radio resources.

An example of the high interference indicator is defined as follows: TheInformation Element/Group Name is: high interference indicator; itspresence is mandatory; the information element type and reference is:BIT STRING (1 . . . 110, . . . ); and the semantics description is: Eachposition in the bitmap represents a PRB (first bit=PRB 0 and so on), forwhich value “'1” indicates ‘high interference sensitivity’ and value “0”indicates ‘low interference sensitivity’. The maximum number of PhysicalResource Blocks is 110.

Thus, an exemplary embodiment includes enabling a base station (210) toretrieve a third set of parameters, named device to device informationelement 3, from a device to device link in adjacent cells that includeload and interference information of the device to device link. Thedevice to device information element 3 is preferably a high interferenceindicator for the sidelink which sends device to device informationelement 3 and it a preferred method includes the setp of sending thehigh interference indicator from a first user equipment in sidelinkcommunications (such user equipment previously referred to as those inthe second plurality of user equipment) to a base station (210) with anindication of a potential transmission between user equipment (105) inthe sidelink communications that could be scheduled in certain parts ofradio resources.

Novel Localization of Mobile Devices in Proximity

A novel feature of a preferred embodiment disclosed herein is alocalization module (500), illustrated in FIG. 5. The localizationmodule (500) is implemented in a mobile device (605) to locate targettransmitters in proximity, as illustrated in FIG. 6B and FIG. 7, by themobile device (605) itself. The mobile device (605) can be for example,a mobile phone, a robot, a car, etc. The target transmitters (610) canbe for example, mobile phones, laptops, a book with a radio transmitter,robots, cars, etc. In FIG. 6B, the mobile device is moving on a path(615) in an area where there are multiple target transmitters (610) andthe mobile device (605) is not connected to the Internet (125).

The target transmitters (610) are considered to be in proximity as longas their signals can be detected by the mobile device (605).

In FIG. 7, the mobile device is connected (705) to the Internet (125)and a remote sever (710) while moving along a path (615) inside an areawhere there are multiple target transmitters (610). The targettransmitters (610) are considered to be in proximity as long as theirsignals can be detected by the mobile device (605).

The main function of the localization module (500) is to locate one orseveral of the target transmitters in proximity to the mobile deviceitself. In one example of the implementation, the localization module(500) guides the movement of the mobile device (605) continuously sothat the mobile device (605) can approach one or more of the targettransmitters of interest. With the localization module (500), two mobileterminals in Long Term Evolution networks will be able to approach eachother for sidelink communications. In addition, for approaching devices,their throughput can be significantly increased while the energyconsumption can be reduced. Meanwhile, approaching devices will alsoincrease the network capacity and enable more simultaneous sidelinkcommunications in Long Term Evolution networks.

The localization module (500) consists of three key components,self-tracking component (505), signal-detection component (510), andlocation-estimation component (515. Other assisting components may beincluded. The key functions of the three key components are describedbelow.

The key function of the self-tracking component (505) is to track themovement, i.e. measures or estimates the movement, of the mobile device(605) and report the measurement results to the location-estimationcomponent (515). FIG. 6A illustrates tracking measurements (600) by theself-tracking component (505) in user equipment.

The self-tracking component (505) is configured to perform measurementsof location information of the mobile device (605) using sensors. Themeasured location information is then reported to thelocation-estimation component (515).

In one example, the self-tracking component (505) in a smart phone, e.g.an IPHONE, can be one that estimates the relative location, movingdirection, steps, of the human being carrying the phone, at any samplingtime instant by using integrated sensors in the phone, e.g.accelerometer, gyroscope and compass. The path (615) or trace of themobile device (605) can therefore be tracked by the self-trackingcomponent (505).

If the mobile device (605) were a car, and the self-tracking component(505) were in the car, then the distance the car travels could bemeasured by counting the number of wheel rotations, and direction oftravel could be measured by angle of steering wheel.

If the mobile device (605) were an airplane, and the self-trackingcomponent (505) were in the airplane, then the path (615) of the flightcould be traced.

If the mobile device (605) were a robot and the self-tracking component(505) were in the robot, then knowing the robot's step size, i.e. movingdistance, and its moving direction, the path (615) could be readilydetermined.

If the mobile device (605) included a Global Positioning System (GPS)component, then the location of the mobile device (605) could beobtained by reading GPS signals.

Thus, an embodiment of the localization module (500) includes: aself-tracking component (505); a signal-detection component (510); and alocation-estimation component (515).

In this embodiment, the self-tracking component (505) comprises sensorsto perform measurements of location information of the localizationmodule (500).

In this embodiment, the signal-detection component (510) detects one ormore signal properties at locations selected from among those where theself-tracking component (505) performs a measurement for distanceinformation between the localization module (500) and one or more targettransmitters (610). See FIG. 6A. The measurements include at least oneof: the distance between the localization module (500) and the one ormore of the target transmitters (610); and received signal strength ofsignals received from said one or more target transmitters (610) by thelocalization module (500). The location-estimation component (515)estimates location information, the location information selected fromthe group consisting of: geographic coordinates where signal propertieswere detected by the signal-detection component (510); alocalization-related parameter for such geographic coordinates based onthe input from the self-tracking component (505) and thesignal-detection component (510); and a direction the localizationmodule (500) would have to go to approach said one or more targettransmitters (610); and wherein the a self-tracking component (505), thesignal-detection component (510) and the location-estimation component(515) are interconnected so as to enable the provision of data to thelocation-estimation component (515). The sensors are selected from thegroup consisting of an accelerometer, a gyroscope, a global positioningsystem that can report its location, and a compass enabling estimationof the relative location and moving direction of the self-trackingcomponent at any sampling time period.

An example of the measurement result by the self-tracking component(505) is illustrated in FIG. 6A: moving direction at the reporting time:d=(dx, dy, dz); and/or

relative coordinate: (x[1], y[1], z[1]), (x[2], y[2], z[2]), (x[3],y[3], z[3]), . . . , (x[k], y[k], z[k]), which is the relative locationof the mobile device itself sampled at k locations on its route. Here(x, y, z) can be a right-handed Cartesian coordinate system,illustrating the x (right-left), y (forward-backward) and z (up-down)axes relative to a human being, a robot, a car, and so on, at thereporting time.

Another example of the measurement result by the self-tracking component(505) is: moving speed at the reporting time: d=(dx/dt, dy/dt, dz/dt);acceleration at the reporting time: a=(d²x/dt², d²y/dt², d²z/dt²). Thelocation information may also comprise the time instances that thelocation information is measured and/or reported.

In the signal-detection component (510), each of the target transmitters(610) is able to broadcast signals that can be detected by thesignal-detection component (510). This component detects a set of signalproperties at each sampling location for each of the target transmitters(610) of interest and reports this information to thelocation-estimation component (515). The sampling locations are thosewhere the self-tracking component (505) performs a measurement.

The sampling locations are not necessarily exactly the physicallocations at which the self-tracking component (505) performs directmeasurements of the physical locations. A direct measurement of thephysical location means: when the mobile device (606) is located at(x[i], y[i], z[i]), the self-tracking component (505) performs themeasurement and obtains the estimates of (x[i], y[i], z[i]) itself. Thesampling locations may be the physical locations where the self-trackingcomponent (505) performs indirect measurements of the locations. Anindirect meansurement of the location means: while the mobile device(606) is located at (x[i], y[i], z[i]), the self-tracking component(505) has performed direct measurement of the location information atthe physical locations at (x[1], y[1], z[1]), . . . , (x[i−1], y[i−1],z[i−1]), (x[i+1], y[i+1], z[i+1]), . . . (x[k], y[k], z[k]), other than(x[i], y[i], z[i]). The location information at these locations, (x[1],y[1], z[1]), . . . , (x[i−1], y[i−1], z[i−1]), (x[i+1], y[i+1], z[i+1]),. . . (x[k], y[k], z[k]), can be used by the self-tracking component(505) or the location estimation component (515) to estimate (x[i],y[i], z[i]). Therefore, the estimate of (x[i], y[i], z[i]) is anindirect estimate as it is based on the direct measurement of thelocation information at locations other than (x[i], y[i], z[i]) itself.The implementation of the estimate of (x[i], y[i], z[i]) can beperformed at the self-tracking component (505), the location estimationcomponent (515), or jointly at both components. In all these cases, wesay the sampling locations are those where the self-tracking component(505) performs a measurement, as both the direct and indirctmeasurements of the sampling locations are based on the locationinformation measured by the self-tracking component (505).

Below, some examples are given relative to one of the targettransmitters (610). Simpler examples can be applied to other targettransmitters of interest. In the examples, the signal properties thatare detected contain information about the distance between the mobiledevice (605) and one of the target transmitters (610). For example, thesignals could be radio signals like Wi-Fi signals, reference signalsbroadcasted by an Evolved Node B in Long Term Evolution networks, thediscovery signals in Device to Device sidelink communications, ordedicated localization signals. These signals may be ultrasonic waves,whose roundtrip traveling time can be used to estimate the distancebetween the mobile device and target terminal.

Additional examples of the signal properties at the sampling locationsare the estimated distance from the target transmitter to the mobiledevice at the k sampling locations, {L[1], L[2], L[3], . . . , L[k]};the received signal strength indicator, {R[1], R[2], R[3], . . . ,R[k]}; the time of signal arrival, {T[1], T[2], T[3], . . . , T[k]};multiple received signal strength indicators for several directions ineach sampling location: {(R[11], d[11]); (R[12], d[12]); . . .},{(R[21], d[21]); (R[22], d[22]); . . . }, . . . , {(R[K1], d[K1]);(R[K2], d[K2]); . . . }}, where R[ij] is the jth received signalstrength indicator at the ith location and d[ij] is the correspondingdirection measurement of the mobile device.

The location-estimation component (515) estimates the location or anylocalization-related parameter for each of the target transmitters (610)of interest based on the input from the self-tracking component (505)and the signal-detection component (510). In one example of theimplementation, the location of a target transmitter (x, y, z) isestimated by finding the maximum likelihood solution to the followingequation group:(x[1]−x)^2+(y[1]−y)^2+(z[1]−z)^2=L[1]^2 ;(x[2]−x)^2+(y[2]−y)^2+(z[2]−z)^2=L[2]^2;. . .(x[k]−x)^2+(y[k]−y)^2+(z[k]−z)^2=L[k]^2;Or other more advanced estimators can be implemented to estimate thelocation based on the signal properties provided by the signal-detectioncomponent (510) and the input from the self-tracking component (505).

In an exemplary embodiment, the location-estimation component (515)estimates which direction the mobile device (605) would have to go toapproach one of the target transmitters (610), that is, (x-x[k], y-y[k],z-z[k]). For example, it may suggest that the mobile device (605) go tothe left or right, forward or backward, up or down, so that it will becloser to the target transmitter.

The location-estimation component (515) may perform all the computationof the location estimation locally by the location-estimation component(515) itself. The location-estimation component (515) may furthercomprise a communications module and offload part or all of thecomputation of the location estimation to another apparatus eitherlocally or remotedly. For example, the location-estimation component(515) may send necessary information based on the input from theself-tracking component (505) and the signal-detection component (510)to a remote server. The remote server performs the estimation of thelocation or any localization-related parameter for each of the targettransmitters (610) of interest and then sends the estimation resultsback to the location-estimation component (515). In the latter case, itis still the location-estimation component (515) that estimates thelocation or any localization-related parameter for each of the targettransmitters (610) of interest based on the input from the self-trackingcomponent (505) and the signal-detection component (510), as thelocation-estimation component (515) collects the inputs from theself-tracking component (505) and the signal-detection component (510)and then obtains the estimation of the location or anylocalization-related parameter for each of the target transmitters (610)of interest.

Therefore in one embodiment of the invention, a location-estimationcomponent (515) comprises an interconnection with a self-trackingcomponent and a signal-detection component. The interconnection enablesprovision of data from said self-tracking component and saidsignal-detection component to the location-estimation component. Thelocation-estimation component is capable of estimating locationinformation based on data provided by the self-tracking component andthe signal-detection component. The computation of the estimation of thelocation information can be implemented either locally or remotely. Forexample the location information can be selected from the groupconsisting of: geographic coordinates of one or more target transmitterswhich broadcast signals that can be detected by the signal-detectioncomponent; a localization-related parameter for such geographiccoordinates; and a direction the location-estimation component wouldhave to go to approach said one or more target transmitters. Theself-tracking component may be configured to perform measurements oflocation information using sensors selected from the group consisting ofan accelerometer, a gyroscope, a global positioning system that canreport its location, and a compass enabling estimation of a relativelocation and moving direction of the self-tracking component at anysampling time period.

To implement the location-estimation component, embodiments furtherprovide a non-transitory computer readable memory storing instructionsthereon. The instructions when implemented on a computer enable thecomputer to use data provided by a self-tracking component and asignal-detection component to implement steps of:

-   -   estimating location information based on data provided by the        self-tracking component and the signal-detection component, the        location information selected from the group consisting of:        geographic coordinates of one or more target transmitters who        broadcast signals that were detected by the signal-detection        component; a localization-related parameter for such geographic        coordinates; and a direction the self-tracking component would        have to go to approach said one or more target transmitters;    -   wherein the self-tracking component comprises sensors capable of        performing measurements of location information of the        self-tracking component; and wherein the signal-detection        component is capable of detecting one or more signal properties        at locations selected from among those where the self-tracking        component performs a measurement and the signal properties        contain distance information between the signal-detection        component and one or more target transmitters.

Proximity System

In an exemplary embodiment, a proximity system also referred to as aproximity platform, is illustrated in FIG.8 and is composed of alocalization module (500), a proximity-description module (805) and aproximity-display module (810) within implemented in the mobile device(605).

The proximity platform is used for locating target transmitters (610),also known as wireless transmitters, in proximity to the mobile device(605) and then to display the relevant information about the targettransmitters (610) on the mobile device (605). In addition, assistingmodules, may be utilized to enhance functionality and add complementaryfeatures to the localization module (500), the proximity-descriptionmodule (805) and the proximity-display module (810).

In this exemplary embodiment, the localization module (500) locatestarget transmitters (610) in proximity to the mobile device (605) andsends their information, e.g. coordinates and ID, to theproximity-description module (805).

In this exemplary embodiment, the proximity-display module (810)displays the information related to all the target transmitters (610)that have been located by the localization module (500). The way thatthe information is preferably displayed is dependent on the locations ofthe target transmitters (610). This information is, for example, thename of the transmitter or of the store where the target transmitter isplaced, an advertisement, promotion coupons, video, photos, commentsfrom visitors, price lists, room and floor numbers, etc.

The information related to all the target transmitters (610) may also bethe direction and distance information for the mobile device (605) toapproach a target transmitter, which has been provided by thelocalization module (500). In this exemplary embodiment, the way theinformation is displayed depends on the locations of the targettransmitters (610). For example, in a top-down mode, the information ofa wireless transmitter that is closer to the mobile device (605) is ontop of the one further away, or the other way round.

An embodiment of the proximity-description module (805) is illustratedin FIG. 9. In addition to assisting components, theproximity-description module (805) may include: a storage component(910), which includes non-transitory computer-readable memory, adescription component (915); an Internet-access component (920) thatprovides an optional connection to the Internet (125) so that theproximity-description module (805) may operate in the on-line oroff-line mode; and a user-interface component (940). Depending on theavailability of Internet access, the proximity-description module (805)is operational in either the online mode (connected to the Internet(125)) or the offline mode (unconnected to the Internet (125)).

In the offline mode, the description component (915) reads from thestorage component (910) any information related to the targettransmitters (610), also referred to as the wireless transmitters, whichhave been located. The description component (915) then sends thatinformation for display. In addition, the description component (915)may also get information from the user-interface component (940) andstore that information in the storage component (910). For example, auser holding the mobile device (605) may take a picture of a store wherea wireless transmitter is located, which is executed by theuser-interface component (940), e.g. a camera. The description component(915) will save the picture to the storage component (910).

In the online mode, the switch (930) shown in FIG. 9 is closedestablishing the connection enabling the description component (915) tocommunicate with the one or more remote servers (935). These one or moreremote servers (935) may include one or more databases. Suchcommunication enables the mobile device (605) to update the informationrelated to the target transmitters (610) that have been located.

For example, the description component (915) may download informationrelated to the target transmitters (610) from the one or more remoteservers (935) and send it to the proximity-display module (810) fordisplay or to the storage component (910) so that it can besynchronized. In addition, the description component (915) may alsoupload the information that has been stored in the storage component(910) to the one or more remote servers (935). The description component(915) may also get information from the user-interface component (940)and store it in the storage component (910) and/or upload it to the oneor more remote servers (935).

The proximity platform may also include a proximity advertisement module(905), as illustrated in FIG. 9 and FIG. 10. The proximity advertisementmodule (905) is an independent module that can be implemented in anydevice that can access the Internet (125), e.g. a smart phone, an iPad,a laptop, a desktop, etc. The main functions of the proximityadvertisement module (905) are illustrated in FIG. 10.

Thus, an embodiment of the proximity system (800) for a wirelesscommunication network (100) includes multiple base stations, whereineach base station (210) is able to send and receive communications (110)in the wireless communication network (100); a plurality of userequipment able to communicate with at least one base station; aplurality of target transmitters that are broadcasting signals, saidplurality of target transmitters able to communicate with at least onebase station, the proximity system (800) usable to locate one or moretarget transmitters (610) in the plurality of target transmitters, theproximity system (800) comprising: a localization module (500); aproximity-description module (805); and a proximity-display module(810).

In this embodiment, the localization module (500) locates one or moretarget transmitters (610) within the plurality of target transmittersand sends proximity information (925) on each located target transmitterto the proximity-description module (805).

In this embodiment, the proximity-description module (805) includes astorage component (910). The storage component (910) includesnon-transitory computer readable memory; a description component (915)that reads the proximity information (925) from the storage component(910) and sends the proximity information (925) to the proximity-displaymodule (810) for display; an Internet-access component (920) thatprovides an optional connection to the Internet; and a user-interfacecomponent (940) that inputs user data to the storage component (910),the user-interface component (940) processes the proximity information(925) and sends proximity information (925) to the proximity-displaymodule (810). In this embodiment, the proximity-display module (810)displays the proximity information (925) in a manner that represents thedistance from the first user equipment.

In this embodiment, the proximity system may utilize proximityinformation that is selected from the group consisting of: coordinatesof each located target transmitter; an identification of each locatedtarget transmitter; a name for each store at each located targettransmitter, an advertisement that may be relevant to each locatedtarget transmitter, a promotion coupon for any store at each locatedtarget transmitter, a video relevant to the area near each locatedaccess point, a photo relevant to the area near each located targettransmitter, any comments received on the area near each located targettransmitter; a price list for products or services available near eachlocated target transmitter; room availability near each located targettransmitter; direction and distance information for the first userequipment to approach the target transmitter, and floor numbers ofbuildings near each located target transmitter.

To implement the proximity system, embodiments further provide anon-transitory computer readable medium storing instructions thereon,the instructions when implemented on a computer enable the computer toreceive proximity information of one or more target transmitters withina plurality of target transmitters from a localization module, theinstructions further enable the computer to implement steps of:

reading or storing information related to said one or more targettransmitters from a storage component that comprises non-transitorycomputer readable memory;

reading and processing information of said one or more targettransmitters using a user-interface component;

downloading or uploading information related to target transmitters fromthe Internet using an Internet access component;

sending the information of said target transmitters to aproximity-display module for display; and

wherein the localization module is capable of estimating the locationinformation of the one or more target transmitters within the aplurality of target transmitters.

The proximity advertisement module (905) includes three main components:an access management component (1005), an ownership management component(1010), and content management component (1015). These three maincomponents may be combined with other assisting components.

The access management component (1005) is used to establish, that is itenables, an Internet connection between the proximity advertisementmodule (905) and one or more remote servers (935), also referred to as aremote server (710).

The ownership management component (1010) is used to upload material, towit, information, to one or more remote servers (935), also referred toas a remote server (735). The information is used to verify theownership of target transmitters (610). For example, a store manager isusing the proximity platform and will provide verification informationthrough the ownership management component (1010) to prove that he isthe owner of the wireless transmitters, aka, target transmitters (610),deployed in his store.

In one example of a preferred embodiment, ownership of the targettransmitters (610) is verified by uploading the MAC address, SSID, or apicture of the bar code on the target transmitter to the one or moreremote servers (935) using the ownership management component (1010). Inone example of a preferred embodiment, ownership of the targettransmitters (610) is verified by uploading information related to thepurchasing receipt for the target transmitters (610) to the one or moreremote servers (935) using the ownership management component (1010).After a wireless transmitter is verified, the information related tothis wireless transmitter is managed or administered through the contentmanagement component (1015) by its owner.

The content management component (1015) is used by the owner to managethe information related to the target transmitters (610) that areverified to the one or more remote servers (935). For example, ageolocation of any of the target transmitters (610) can be uploaded tothe one or more remote servers (935) by the owner using the contentmanagement component (1015). The floorplan of the building where each ofthe target transmitters (610) is located can be uploaded to the one ormore remote servers (935) by the owner using the content managementcomponent (1015). Store description, sales promotion, advertisement,price list, and so on of the store that owns the target transmitter(610) can be uploaded to the one or more remote servers (935) by theowner using the content management component (1015). The sameinformation, e.g. promotion advertisement and price list, may beuploaded for a group of verified wireless transmitters to the one ormore remote servers (935) by the owner.

To implement the proximity advertisement module (905), a non-transitorycomputer readable medium may store instructions thereon, and theinstructions enable the computer to implement steps of:

using an Internet connection between said computer and one or moreremote servers to upload material of a target transmitter in theplurality of target transmitters to said one or more remote servers; and

manage the proximity information of each verified target transmitter tothe said one or more remote servers,

wherein said material can be used to verify ownership of a targettransmitter in the plurality of target transmitters that once verifiedbecomes a verified target transmitter;

An Implementation Example

A detailed implementation example of the invented interferencecoordination technollogies.

Define φxk ∈{0, 1}, ∀x ∈{1, . . . , N}∀k ∈{1, . . . , N^x}, as a binaryrandom variable that indicates the state of a Device to Device link. Forφxk=1 the Device to Device link k in cell x is active, i.e. in thedevice to device mode, otherwise φxk=0. The parameter N corresponds tothe number of cells in the system and N^x is the number of availabledevice to device links in cell x.

The maximum level of interference that can be tolerated in the system isgiven by the Signal-to-Interference-plus-Noise Ratio requirements forthe Cellular User Equipment and device to device links, depicted in(2.1a) and (2.1b), respectively. An upper bound for the transmissionpower of device to device links shown in (2.1c).

$\begin{matrix}{{\Gamma_{x\; 0} = {\frac{P_{x\; 0}G_{x\; 0x\; 0}}{I_{x\; 0}^{D\; 2\; D} + I_{x\; 0}^{CUE} + {??}_{BS}} \geq \gamma_{x\; 0}^{th}}},} & \left( {2.1a} \right) \\{{\Gamma_{x\; k} = {\frac{\phi_{x\; k}P_{x\; k}G_{x\; k\; x\; k}}{I_{x\; k}^{D\; 2\; D} + I_{x\; k}^{CUE} + {??}_{D}} \geq \gamma_{x\; k}^{th}}},} & \left( {2.1b} \right) \\{{{\phi_{xk}P_{xk}} \leq P_{D}^{{ma}\; x}},{\forall{x \in {\left\{ {1,\ldots\mspace{14mu},N} \right\}\mspace{14mu}{\forall{k \in {\left\{ {1,\ldots\mspace{14mu},{\hat{N}}_{x}} \right\}.}}}}}}} & \left( {2.1c} \right)\end{matrix}$

The terms I^(D2D) and I^(CUE) correspond to the interference received atthe base stations x0 and x0 of cell x, from the device to device linksand Cellular User Equipment, respectively. Similarly I_(xk) ^(D2D) andI_(xk) ^(CUE) correspond to the interference received at the Device toDevice link k of cell x from other device to device links and CellularUser Equipment, respectively. N_(BS) and N_(D) are the noise power atthe base stations and device to device links receivers respectively.P_(x0) corresponds to the transmission power from the Cellular UserEquipment at cell x. P_(xk) is the power of the transmitting device ofdevice to device pair k in cell x and P max is the maximum transmissionpower of device to device links. γ_(x0) ^(th) and γ_(xk) ^(th) representthe target Signal-to-Interference-plus-Noise Ratio of the Cellular UserEquipment uplink and the Device to Device link k in cell x,respectively.

The term G is the channel gain and has a subscript formed using ageneral rule. For example the general rule is that a subscript “abij” inG_(abij) corresponds to the channel gain from the transmitter “b” incell “a” to the receiver “j” in cell “i”. Note that in all variables,cellular user equipment and base stations are indexed as “0” and Deviceto Device users are indexed with integer numbers greater than zero. Inequations (2.1a) and (2.1b), G_(x0x0) corresponds to the channel gainbetween the Cellular User Equipment and the base stations of cell x,while G_(xkxk) corresponds to the channel gain between the transmitterand receiver of device to device pair k in cell x.

Thus, the interference terms are defined as:

$\begin{matrix}{{I_{x\; 0}^{D\; 2\; D} = {\sum\limits_{i = 1}^{N}{\sum\limits_{j = 1}^{N_{i}}{\phi_{ij}P_{ij}G_{{ij}\; x\; 0}}}}},} & \left( {2.1a} \right) \\{{I_{x\; 0}^{CUE} = {\sum\limits_{\underset{i \neq x}{i = 1}}^{N}{P_{i\; 0}G_{i\; 0x\; 0}}}},} & \left( {2.1b} \right) \\{{I_{x\; k}^{D\; 2\; D} = {{\sum\limits_{i = 1}^{N}{\sum\limits_{j = 1}^{{\hat{N}}_{i}}{\phi_{ij}P_{ij}G_{ijxk}}}} - {\phi_{xk}P_{xk}G_{xkxk}}}},} & \left( {2.1c} \right) \\{{I_{xk}^{CUE} = {\sum\limits_{i = 1}^{N}{P_{i\; 0}G_{i\; 0\;{xk}}}}},} & \left( {2.1d} \right) \\{\forall{x \in {\left\{ {1,\ldots\mspace{14mu},N} \right\}\mspace{14mu}{\forall{k \in {\left\{ {1,\ldots\mspace{14mu},{\hat{N}}_{x}} \right\}.}}}}}} & \;\end{matrix}$

From equations (2.1a) and (2.1b), there are two levels of interferencein the network. The Signal-to-Interference-plus-Noise Ratio target forcellular user equipment (CUE) is redefined as:

$\begin{matrix}{{\gamma_{x\; 0}^{th} = {\frac{\Gamma_{x\; 0}^{i}}{\delta} = \frac{P_{x\; 0}G_{x\; 0x\; 0}}{\left( {I_{x\; 0}^{CUE} + {??}_{BS}} \right)\delta}}},{\forall{\delta \in \left\{ {{\mathbb{R}}^{+};{\delta > 1}} \right\}}},} & (2.3)\end{matrix}$

where Γ_(x0) ^(i) is the average Signal-to-Interference-plus-Noise Ratioof Cellular User Equipment before device to device links are added tothe system. The parameter δ corresponds to the desired ratio between theCellular User Equipment's Signal-to-Interference-plus-Noise Ratio beforeand after device to device links are added, i.e., theSignal-to-Interference-plus-Noise Ratio loss of Cellular User Equipmentdue to device to device links and this parameter is carried in the newlycreated Device to Base Stations Information Element.

This definition allows a clear evaluation of the impact of device todevice links to the Cellular User Equipment uplink, thus the Quality ofService (QoS) of Cellular User Equipment is defined as theSignal-to-Interference-plus-Noise Ratio loss being below the desiredtarget δth. For the device to device links, the Quality of Service isdefined as the Signal-to-Interference-plus-Noise Ratio being above agiven threshold γth xk. The target Signal-to-Interference-plus-NoiseRatio for device to device links is γ^(th)xk=yD .

Consider a victim receiver v surrounded by N devices. The aggregatedinterference, I, received at v as:

$\begin{matrix}{{I_{v} = {\sum\limits_{i = 1}^{\overset{\sim}{N}}{P_{t\; x_{v\; i}}G_{v\; i}^{I}}}},} & (2.4)\end{matrix}$

where P_(txvi) is the transmission power of an interfering device i andG_(vi) ^(I) is the channel gain between v and i.

Assume that interfering devices are randomly distributed within a givenarea A. Thus the channel gains can be represented as a random variableG_(vi) . It is also assumed that the interfering devices have the sametransmission power P_(txvi)=P_(tx)≤P_(max), where P_(max) is the maximumtransmission power allowed by regulatory entities or the poweramplifier. The expected value for the aggregated interference within Ais:

[I _(v)]=Ñ _(A) AP _(tx)

[G _(vi)],  (2.5)where A Ψ_(A) is the number of interfering devices per unit area, andcan be derived by using Device to Device Information Element.

Define A=π(dw)² as a circular interference area around v where dw is themaximum distance between v and an interfering device. Notice that theinterference caused by devices outside of A is negligible compared tointerference caused by the users inside due to the path lossattenuation. For example, d_(w) can be defined as:

$\begin{matrix}{{{P_{m\; a\; x}{{??}\left\lbrack G_{vw} \right\rbrack}} < {??}_{v}},} & (2.6) \\{{{d_{vw} > \left( \frac{P_{m\; a\; x}c_{v}{{??}\left\lbrack {h_{vw}}^{2} \right\rbrack}}{{??}_{v}} \right)^{1/\alpha_{v}}} = d_{w}},} & \;\end{matrix}$

where N_(v) is the noise power at the victim receiver and d_(vi) is thedistance between devices v and i. The channel gain between v and i as:G _(vi) =c _(v) d _(vi) ^(−α) ^(v) |h _(vi)|²,  (2.7)where c_(v) refers to a propagation constant and α_(v), is the path lossexponent. The effects of fading are represented by |h_(vi)|². Thismetric means the interference out of the circular area is weaker thanthermal noise.

The expected value of G_(vi) is:

[G _(vi)]=c _(v)

[d _(vi) ^(−α) ^(v) ]

[|h _(vi)|²].  (2.8)

It is assumed that device v to be located at a fixed point and device ito be positioned randomly following a circular distribution around v.Thus, the probability density function of d_(vi) is given by atriangular distribution depicted as:

$\begin{matrix}{{f_{d_{vi}}(x)} = \left\{ \begin{matrix}\frac{2\; x}{\left( d_{m\; a\; x} \right)^{2}} & {{{{if}\mspace{14mu} d_{m\; i\; n}} \leq x \leq d_{{m\;{ax}}\;}},} \\0 & {{otherwise}.}\end{matrix} \right.} & (2.9)\end{matrix}$

Combining (2.8) and (2.9) we have that ∀αv ∈{R+;αv>2}.

$\begin{matrix}\begin{matrix}{{{??}\left\lbrack G_{vi} \right\rbrack} = {c_{v}{{??}\left\lbrack {h_{vi}}^{2} \right\rbrack}{\int_{d_{m\; i\; n}}^{d_{m\; a\; x}}{x^{- \alpha_{v}}{f_{d_{v\; i}}(x)}d\; x}}}} \\{= {c_{v}{{??}\left\lbrack {h_{vi}}^{2} \right\rbrack}{\int_{d_{m\; i\; n}}^{d_{m\; a\; x}}{\frac{2\; x^{({1 - \alpha_{v}})}}{\left( d_{{m\; a\; x}\;} \right)^{2}}d\; x}}}} \\{= {\frac{2\; c_{v}{{??}\left\lbrack {h_{vi}}^{2} \right\rbrack}\left( {d_{m\; i\; n}^{- {({\alpha_{v} - 2})}} - d_{m\; a\; x}^{- {({\alpha_{v} - 2})}}} \right)}{\left( d_{m\; a\; x} \right)^{2}\left( {\alpha_{v} - 2} \right)}.}}\end{matrix} & (2.10)\end{matrix}$

Assume the channel to be invariant during the period of interest, thusit is assumes that E[|h_(vi)|²]=1. Note also that for practicalapplications, the probability density function of d_(vi) can be changedto match real users distribution. Then, the expected interference to avictim in an area using (2.5), which is a generic formula and can beused to determine the mode selection procedures.

Consider a device to device pair k in a cell x, denoted by D2D_(Xk),that needs to decide its operating mode, i.e. Device to Device orcellular mode. Define the upper and lower bound for the transmissionpower as P_(D) _(xk) ^(UB) and P_(D) _(xk) ^(LB), respectively.

To obtain the upper bound first, the term I_(x0) ^(D2D) found in (2.2a),is defined as:I _(x0) ^(D2D)=φ_(xk) P _(xk) G _(xkx0)+Î_(x0) ^(D2D)=φ_(xk) P _(D)_(xk) G _(xkx0)+Î _(x0) ^(D2D),  (3.12)where Î_(x0) ^(D2D) corresponds to the aggregated interference caused byactive Device to Device links to the base stations of cell x (BS_(sx)).Since D2D_(xk) does not have Channel

State Information (CSI) to calculate Î_(x0) ^(D2D), it is considered tobe a random variable, thus its expected value is calculated by applyingthe interference model presented above.

As a result, the equation is:

$\begin{matrix}{{{{??}\left\lbrack {\hat{I}}_{x\; 0}^{D\; 2\; D} \right\rbrack} = {\frac{{\overset{\sim}{N}}_{x}}{A_{c\; l_{x}}}A_{x\; 0}P_{D_{x\; k}}{{??}\left\lbrack G_{{D\; 2\; D} - {B\; S}} \right\rbrack}}},} & (3.13)\end{matrix}$

where A_(x0) is the interference area and A_(cIx) is the area of cell x.The term E[G_(D2D-BS)] is the expected value of the channel gain betweenactive device to device links and base stations.

The statistical upper bound for the transmission power of device todevice links P_(D) _(xk) ^(UB) by combining the expected value of (2.1a)and (2.1c) with (3.13), thus P_(D) _(xk) ^(UB) is given by:

$\begin{matrix}{{P_{D_{x\; k}}^{U\; B} = {\min\left\{ {\frac{{\hat{I}}_{x\; 0}^{t\; h}}{G_{x\; k\; x\; 0} + {\frac{{\overset{\sim}{N}}_{x}}{A_{{cl}_{x}}}A_{x\; 0}{{??}\left\lbrack G_{{D\; 2\; D} - {BS}} \right\rbrack}}},P_{D}^{m\; a\; x}} \right\}}},} & (3.14)\end{matrix}$Î _(x0) ^(th)=(I _(x0) ^(th)−

[I _(x0) ^(CUE)]−N _(BS)),•x ∈{1, . . . , N}∀k∈{1, . . . , {circumflex over (N)} _(x)}.where G_(xkx0) corresponds to the instantaneous channel gain betweenD2D_(xk) and BS_(sx), which can be estimated using the downlinkreference signals.

The term I_(x0) ^(CUE) is considered to be a random variable and can beestimated by applying the interference model presented in the above. Theparameter Î_(x0) ^(th) , is the total amount of interference that thedevice to device links cause to the base stations x so that the Qualityof Service of the Cellular User Equipment can be assured.Î_(x0) ^(th) may be carried in Device to Device Information Element.

To obtain the lower bound for the transmission power, theSignal-to-Interference-plus-Noise Ratio requirement of device to devicelinks in (2.1b), where the term I_(xk) ^(D2D) represents theinterference from other active device to device links to D2D_(xk) andcan be estimated as:

$\begin{matrix}{{{??}\left\lbrack I_{x\; k}^{D\; 2\; D} \right\rbrack} = {\frac{N_{x\; d}}{A_{d\; x}}A_{x\; k}P_{D}{{{??}\left\lbrack G_{{D\; 2\; D} - I} \right\rbrack}.}}} & \;\end{matrix}$

Here the parameter Axk is the interference area and E[G_(D2D-I)] is theexpected value of the channel gain between an interfering Device toDevice link (within Axk) and D2D_(xk).

To estimate the number of active device to device links per unit area inthe surrounding area of D2D_(xk) we assume that the cells are dividedinto three sectors (1110), (1111) and (1112), which is highly common inpractical applications like Long Term Evolution-A, as illustrated inFIG. 11.

Thus, base station x, BS_(x) (1120), BS_(y) (1121), and BS_(z) (1122),can know the number of active device to device links on each sector andthis could be broadcasted to the users using Device to DeviceInformation Element and exchanged among base stations using Device toDevice Information Element 2. Nxd in the calculation (1125) representsthe sum of active device to device links in the three sectors (1110),(1111) and (1112) that are closer to D2Dxk and Adk is the area enclosedby such sectors.

By calculating the expected value of (2.1b) and combining it with(3.16), a statistical lower bound for the transmission power of deviceto device links is obtained as follows:

$\begin{matrix}{{P_{D_{xk}}^{LB} = \frac{\left( {{{??}\left\lbrack I_{xk}^{CUE} \right\rbrack} + {??}_{D}} \right)A_{dk}\gamma_{D}}{{G_{xkxk}A_{dx}} - \left( {\gamma_{D}\frac{{\overset{\sim}{N}}_{xd}}{A_{dk}}A_{xk}{{??}\left\lbrack G_{{D\; 2\; D} - I} \right\rbrack}} \right)}},} & (3.17) \\{\forall{x \in {\left\{ {1,\ldots\mspace{14mu},N} \right\}\mspace{14mu}{\forall{k \in {\left\{ {1,\ldots\mspace{14mu},{\hat{N}}_{x}} \right\}.}}}}}} & \;\end{matrix}$

The term G_(xkxk) corresponds to the channel gain between thetransmitter and receiver of D2D_(xk) which is obtained from thediscovery procedure. The parameter I_(xk) ^(CUE) corresponds to theinterference caused by Cellular User Equipment towards D2Dxk and can beestimated locally.

Finally the mode selection of Device to Device xk is given by:

$\begin{matrix}{\phi_{xk} = \left\{ {\begin{matrix}{{1\mspace{14mu}{if}\mspace{14mu} P_{D_{x\; k}}^{LB}} \leq P_{D_{xk}}^{UB}} \\{{0\mspace{14mu}{if}\mspace{14mu} P_{D_{xk}}^{LB}} > P_{D_{xk}}^{UB}}\end{matrix},} \right.} & \left( {3.18a} \right) \\{{P_{xk} = {\phi_{xk}P_{D_{xk}}^{LB}}},} & \left( {3.18b} \right) \\{\forall{x \in {\left\{ {1,\ldots\mspace{14mu},N} \right\}\mspace{14mu}{\forall{k \in {\left\{ {1,\ldots\mspace{14mu},{\hat{N}}_{x}} \right\}.}}}}}} & \;\end{matrix}$

The transmission power can also use other formulas to determine, forexample, 3GPP Long Term Evolution-A closed-loop power control.

In this implementation each of the base stations needs to broadcast alimited number of parameters using Device to Device Information Elementor Device to Base Stations Information Element that are common to alldevice to device links. The base stations may also exchange Device toDevice Information Element 2.

Below are several examples of the information that may be carried inDevice to Device Information Element or Device to Base StationsInformation Element in the implementation.

1. Density or number of active device to device links in each cell orsector. This information can be carried in Device to Device InformationElement.

2.I _(x0) ^(th)=(I _(x0) ^(th)−

[I _(x0) ^(CUE)]−N _(BS)),the total amount of interference from the device to device links that istolerable by the Cellular User Equipment uplink of a cell. It can becarried in Device to Base Stations Information Element.

3. c0, cd , α0, αd : propagation constants related to the channel model.They can be carried in either Device to Device Information Element orDevice to Base Stations Information Element.

4. Area of each cell or sector. This can be carried in Device to BaseStations Information Element or Device to Device Information Element.

5. Average sum channel gain of existing device to device links to thebase stations:

$\frac{{\overset{\sim}{N}}_{x}}{A_{{cl}_{x}}}A_{x\; 0}{{??}\left\lbrack G_{{D\; 2\; D} - {BS}} \right\rbrack}$this can be carried in Device to Base Stations Information Element, asthis information can be used to determine the amount of interferencegenerated from device to device links to the primary users.

FIG. 12 illustrates an example role of the implementation (1200) of thenovel signal steps and procedures between a device to device pair andits serving Base Stations. The procedures performed by base station x(1120) and a D2D pair k (1210) within the implementation. The basestation x (1205) (BS x) keeps track of the number (N_(r)) of activedevice to device links, calculates the amount of interference that the

Cellular User Equipment uplink can tolerate, Î_(x0) ^(th), andbroadcasts these and other necessary parameters so that the device todevice links can determine their modes.

At the same time the device to device pairs receive the parametersbroadcast by base station x (1120) (also referred to as BSx), calculatethe upper bounds and lower bounds for their transmission power andnotify base station x (1120) of the mode suggestion. A pictorialrepresentation of the signaling flow (1300) of the above describedimplementation of the invention (Left: base stations, Right: Device toDevice) is illustrated in FIG. 13.

FIG. 14 graphically illustrates the simulation parameters andperformance (1400) of the implementation in a multi-cell cellularnetwork. It shows a charging data function (CDF) of overall performancefor D2D signal to interference plus noise ratio γD=16 dB, the tolerablesignal to interference plus noise ratio of cellular UEδ=2 dB. Thesimulation parameters used are as follows: Radius=R=400 meters; Noisepower=−174 dBm/Hz; Resource Block Bandwidth: Bw=180 kHz; CarrierFrequency=fc=2 GHz=2 gigaHertz; Maximum transmission power=Pmax=23 dBm;Minimum distance between the base stations and the UEs=dmin=10 meters;Device to Device distance (dD2D) limits are: Dmin=10 meters; and Dmax=40meters; Number of cells=N=7; Path loss coefficient (UE to basestations)=CO=−30.55 dB; Path loss coefficient (UE to UE)=cd=−28.03 dB;Path loss experienced (user to base stations)=∀0=3.67; Path lossexperienced (UE to UE)=∀d=4.

The above implementation in a multi-cell cellular network illustrated inFIG. 14 follows Long Term Evolution-A standardization. In each graph ofFIG. 14, the Distributed Admission Control (DAC) is the implementationexample of the invented approach. Distributed Admission Control, OpenLoop Power Control (DAC, OLPC) is the approach using DistributedAdmission Control as the mode selection algorithm while the Long TermEvolution-A open loop power control is applied for determining thetransmission power of device to device pairs.

SINR is the signal-to-interference-plus-noise ratio. CDF is thecumulative distribution.

Optimal admission control (OAC) is the globally optimal algorithm thatassumes full channel state information in a central scheduler who canschedule the transmission of all devices. This serves as the performanceupper bound for Device to Device systems and can never be implemented inpractice.

Blind admission control (BAC) is the blind mode selection algorithmwhere device to device pairs are randomly chosen to be in device todevice mode. Thus, the example shows that a significant throughputimprovement results from using the invented approach, while havingnegligible performance impact on the primary UE.

Certain embodiments of the present disclosure are described above withreference to block and flow diagrams of systems and methods and/orcomputer program products according to example embodiments of thepresent disclosure. It will be understood that one or more blocks of theblock diagrams and flow diagrams, and combinations of blocks in theblock diagrams and flow diagrams, respectively, can be implemented bycomputer-executable program instructions. Likewise, some blocks of theblock diagrams and flow diagrams may not necessarily need to beperformed in the order presented, or may not necessarily need to beperformed at all, according to some embodiments of the presentdisclosure.

These computer-executable program instructions may be loaded onto ageneral-purpose computer, a special-purpose computer, a processor, orother programmable data processing apparatus to produce a particularmachine, such that the instructions that execute on the computer,processor, or other programmable data processing apparatus create meansfor implementing one or more functions specified in the flow diagramblock or blocks. These computer program instructions may also be storedin a computer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meansthat implement one or more functions specified in the flow diagram blockor blocks. As an example, embodiments of the present disclosure mayprovide for a computer program product, comprising a computer-usablemedium having a computer-readable program code or program instructionsembodied therein, said computer-readable program code adapted to beexecuted to implement one or more functions specified in the flowdiagram block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operational elements or steps to be performed onthe computer or other programmable apparatus to produce acomputer-implemented process such that the instructions that execute onthe computer or other programmable apparatus provide elements or stepsfor implementing the functions specified in the flow diagram block orblocks.

Accordingly, blocks of the block diagrams and flow diagrams supportcombinations of means for performing the specified functions,combinations of elements or steps for performing the specified functionsand program instruction means for performing the specified functions. Itwill also be understood that each block of the block diagrams and flowdiagrams, and combinations of blocks in the block diagrams and flowdiagrams, can be implemented by special-purpose, hardware-based computersystems that perform the specified functions, elements or steps, orcombinations of special-purpose hardware and computer instructions.

While certain embodiments of the present disclosure have been describedin connection with what is presently considered to be the most practicaland various embodiments, it is to be understood that the presentdisclosure is not to be limited to the disclosed embodiments, but isintended to cover various modifications and equivalent arrangementsincluded within the scope of the appended claims. Although specificterms are employed herein, they are used in a generic and descriptivesense only and not for purposes of limitation.

This written description uses examples to disclose certain embodimentsof the present disclosure, including the best mode, and also to enableany person skilled in the art to practice certain embodiments of thepresent disclosure, including making and using any devices or systemsand performing any incorporated methods. The patentable scope of certainembodiments of the present disclosure is defined in the claims, and mayinclude other examples that occur to those skilled in the art. Suchother examples are intended to be within the scope of the claims if theyhave structural elements that do not differ from the literal language ofthe claims, or if they include equivalent structural elements withinsubstantial differences from the literal language of the claims.

The article 19 amendments of parent application PCT/US2015/058819 assubmitted on Mar. 14, 2016 (and published on Jun. 2, 2016) withstatement of support on the original application PCT/US2015/058819 areincorporated herein by reference in their entirity.

INDUSTRIAL APPLICABILITY

The invention has application at least to the information andcommunication technology industry.

What is claimed is:
 1. A location-estimation component comprising: aninterconnection with a self-tracking component and a signal-detectioncomponent, the interconnection enabling provision of data to thelocation-estimation component, the location-estimation component capableof estimating location information based on data provided by theself-tracking component and the signal-detection-component, the locationinformation selected from the group consisting of: geographiccoordinates of one or more target transmitters which broadcast signalsthat can be detected by the signal-detection component; alocalization-related parameter for such geographic coordinates; and adirection the location-estimation component would have to go to approachsaid one or more target transmitters; wherein the self-trackingcomponent comprises sensors configured to perform measurements oflocation information of the location-estimation component; and whereinthe signal-detection component is configured to detect one or moresignal properties at locations selected from among those where theself-tracking component performs a measurement and the signal propertiescontain distance information between the location-estimation componentand said one or more target transmitters.
 2. The location-estimationcomponent of claim 1, wherein the self-tracking component is configuredto perform measurements of location information using sensors selectedfrom the group consisting of an accelerometer, a gyroscope, a globalpositioning system that can report its location, and a compass enablingestimation of a relative location and moving direction of theself-tracking component at any sampling time period.
 3. A non-transitorycomputer readable medium storing instructions thereon, said instructionscomprising: instructions when implemented on a computer enable thecomputer to receive proximity information of one or more targettransmitters within a plurality of target transmitters from alocalization module, the instructions further enable the computer toimplement steps of: reading or storing information related to said oneor more target transmitters from a storage component that comprisesnon-transitory computer readable memory; reading and processinginformation of said one or more target transmitters using auser-interface component; downloading or uploading information relatedto target transmitters from the Internet using an optional Internetaccess component; sending the information of said target transmitters toa proximity-display module for display; and wherein the localizationmodule is capable of estimating location information of the one or moretarget transmitters within the a plurality of target transmitters andcomprises a self-tracking component, a signal-detection component, and alocation-estimation component; wherein the location-estimation componentis configured to estimate location information based on data provided bythe self-tracking component and the signal-detection component, thelocation information selected from the group consisting of: geographiccoordinates of said one or more target transmitters who broadcastsignals that were detected by the signal-detection component; alocalization-related parameter for such geographic coordinates; and adirection the localization module would have to go to approach said oneor more target transmitters; and wherein the self-tracking component,the signal-detection component and the location-estimation component areinterconnected so as to enable provision of data to thelocation-estimation component.
 4. The non-transitory computer readablemedium of claim 3, wherein the proximity information is selected fromthe group consisting of: coordinates of each located target transmitter;an identification of each located target transmitter; a name for eachstore at each located target transmitter, an advertisement that may berelevant to each located target transmitter, a promotion coupon for anystore at each located target transmitter, a video relevant to an areanear each located access point, a photo relevant to the area near eachlocated target transmitter, any comments received on the area near eachlocated target transmitter; a price list for products or servicesavailable near each located target transmitter; room availability neareach located target transmitter; direction and distance information forany such user equipment in the plurality of user equipment to approachthe target transmitter, and floor numbers of buildings near each locatedtarget transmitter.
 5. The non-transitory computer readable medium ofclaim 3, storing instructions thereon, the instructions further enablethe computer to implement steps of: using an Internet connection betweensaid computer and one or more remote servers to upload material of atarget transmitter in the plurality of target transmitters to said oneor more remote servers; and manage the proximity information of eachverified target transmitter to the said one or more remote servers,wherein said material can be used to verify ownership of a targettransmitter in the plurality of target transmitters that once verifiedbecomes a verified target transmitter.